diff --git a/core/modules/action/tests/src/Functional/ActionListTest.php b/core/modules/action/tests/src/Functional/ActionListTest.php
index 28eda68187..47f29e1405 100644
--- a/core/modules/action/tests/src/Functional/ActionListTest.php
+++ b/core/modules/action/tests/src/Functional/ActionListTest.php
@@ -16,7 +16,7 @@ class ActionListTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['action'];
+  protected static $modules = ['action'];
 
   /**
    * Tests the behavior when there are no actions to list in the admin page.
diff --git a/core/modules/action/tests/src/Functional/ActionUninstallTest.php b/core/modules/action/tests/src/Functional/ActionUninstallTest.php
index 5b01099fd2..8c7e6ac65c 100644
--- a/core/modules/action/tests/src/Functional/ActionUninstallTest.php
+++ b/core/modules/action/tests/src/Functional/ActionUninstallTest.php
@@ -17,7 +17,7 @@ class ActionUninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'action'];
+  protected static $modules = ['views', 'action'];
 
   /**
    * Tests Action uninstall.
diff --git a/core/modules/action/tests/src/Functional/BulkFormTest.php b/core/modules/action/tests/src/Functional/BulkFormTest.php
index ec6ca482bc..fbf32b2e96 100644
--- a/core/modules/action/tests/src/Functional/BulkFormTest.php
+++ b/core/modules/action/tests/src/Functional/BulkFormTest.php
@@ -18,7 +18,7 @@ class BulkFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'action_bulk_test'];
+  protected static $modules = ['node', 'action_bulk_test'];
 
   /**
    * Tests the bulk form.
diff --git a/core/modules/action/tests/src/Functional/ConfigurationTest.php b/core/modules/action/tests/src/Functional/ConfigurationTest.php
index 9b9dcf62a0..cc384844c2 100644
--- a/core/modules/action/tests/src/Functional/ConfigurationTest.php
+++ b/core/modules/action/tests/src/Functional/ConfigurationTest.php
@@ -18,7 +18,7 @@ class ConfigurationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['action'];
+  protected static $modules = ['action'];
 
   /**
    * Tests configuration of advanced actions through administration interface.
diff --git a/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionConfigsTest.php b/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionConfigsTest.php
index bd87724cf2..337f033670 100644
--- a/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionConfigsTest.php
+++ b/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateActionConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['action'];
+  protected static $modules = ['action'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionsTest.php b/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionsTest.php
index 928b3c9b81..7e5a68607a 100644
--- a/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionsTest.php
+++ b/core/modules/action/tests/src/Kernel/Migrate/d6/MigrateActionsTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateActionsTest extends MigrateDrupal6TestBase {
 
-  public static $modules = ['action', 'comment', 'node'];
+  protected static $modules = ['action', 'comment', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionConfigsTest.php b/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionConfigsTest.php
index 0b1a2caae5..13b31881d1 100644
--- a/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionConfigsTest.php
+++ b/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateActionConfigsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['action'];
+  protected static $modules = ['action'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionsTest.php b/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionsTest.php
index 47049f33c6..45f24fbaa8 100644
--- a/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionsTest.php
+++ b/core/modules/action/tests/src/Kernel/Migrate/d7/MigrateActionsTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateActionsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['action', 'comment', 'node'];
+  protected static $modules = ['action', 'comment', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/action/tests/src/Kernel/Plugin/Action/EmailActionTest.php b/core/modules/action/tests/src/Kernel/Plugin/Action/EmailActionTest.php
index a47f9b35f7..fd3954a745 100644
--- a/core/modules/action/tests/src/Kernel/Plugin/Action/EmailActionTest.php
+++ b/core/modules/action/tests/src/Kernel/Plugin/Action/EmailActionTest.php
@@ -16,7 +16,7 @@ class EmailActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'action', 'dblog'];
+  protected static $modules = ['system', 'user', 'action', 'dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/action/tests/src/Kernel/Plugin/migrate/source/ActionTest.php b/core/modules/action/tests/src/Kernel/Plugin/migrate/source/ActionTest.php
index 938752ad4d..e70f88e43a 100644
--- a/core/modules/action/tests/src/Kernel/Plugin/migrate/source/ActionTest.php
+++ b/core/modules/action/tests/src/Kernel/Plugin/migrate/source/ActionTest.php
@@ -15,7 +15,7 @@ class ActionTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['action', 'migrate_drupal', 'system'];
+  protected static $modules = ['action', 'migrate_drupal', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/src/Tests/AggregatorTestBase.php b/core/modules/aggregator/src/Tests/AggregatorTestBase.php
index f42248975a..f8b5e5c0f4 100644
--- a/core/modules/aggregator/src/Tests/AggregatorTestBase.php
+++ b/core/modules/aggregator/src/Tests/AggregatorTestBase.php
@@ -27,7 +27,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'aggregator', 'aggregator_test', 'views'];
+  protected static $modules = ['block', 'node', 'aggregator', 'aggregator_test', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/AggregatorRenderingTest.php b/core/modules/aggregator/tests/src/Functional/AggregatorRenderingTest.php
index b03ddf88db..e2e3beff05 100644
--- a/core/modules/aggregator/tests/src/Functional/AggregatorRenderingTest.php
+++ b/core/modules/aggregator/tests/src/Functional/AggregatorRenderingTest.php
@@ -17,7 +17,7 @@ class AggregatorRenderingTest extends AggregatorTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'test_page_test'];
+  protected static $modules = ['block', 'test_page_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/aggregator/tests/src/Functional/AggregatorTestBase.php b/core/modules/aggregator/tests/src/Functional/AggregatorTestBase.php
index ddd98bb82f..92c6f91ed7 100644
--- a/core/modules/aggregator/tests/src/Functional/AggregatorTestBase.php
+++ b/core/modules/aggregator/tests/src/Functional/AggregatorTestBase.php
@@ -24,7 +24,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'aggregator', 'aggregator_test', 'views'];
+  protected static $modules = ['block', 'node', 'aggregator', 'aggregator_test', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php b/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
index 557720658d..07d27d832f 100644
--- a/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
+++ b/core/modules/aggregator/tests/src/Functional/DeleteFeedTest.php
@@ -14,7 +14,7 @@ class DeleteFeedTest extends AggregatorTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Deletes a feed and ensures that all of its services are deleted.
diff --git a/core/modules/aggregator/tests/src/Functional/FeedCacheTagsTest.php b/core/modules/aggregator/tests/src/Functional/FeedCacheTagsTest.php
index 0cf6d1d031..f26bb93d22 100644
--- a/core/modules/aggregator/tests/src/Functional/FeedCacheTagsTest.php
+++ b/core/modules/aggregator/tests/src/Functional/FeedCacheTagsTest.php
@@ -17,7 +17,7 @@ class FeedCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/FeedLanguageTest.php b/core/modules/aggregator/tests/src/Functional/FeedLanguageTest.php
index 7e3d672c06..fc2b8051aa 100644
--- a/core/modules/aggregator/tests/src/Functional/FeedLanguageTest.php
+++ b/core/modules/aggregator/tests/src/Functional/FeedLanguageTest.php
@@ -19,7 +19,7 @@ class FeedLanguageTest extends AggregatorTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * List of langcodes.
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonBasicAuthTest.php
index 58bb47351a..73c61d82d2 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FeedHalJsonBasicAuthTest extends FeedHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonTestBase.php b/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonTestBase.php
index 7fa2870012..22357bf0f4 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonTestBase.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/FeedHalJsonTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonAnonTest.php b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonAnonTest.php
index 20d37fa1ee..4823d65b9e 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonAnonTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonAnonTest.php
@@ -14,7 +14,7 @@ class ItemHalJsonAnonTest extends ItemHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonBasicAuthTest.php
index 767c7025a4..f6162675f6 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ItemHalJsonBasicAuthTest extends ItemHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonCookieTest.php b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonCookieTest.php
index 161a735766..c5b41c59aa 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonCookieTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonCookieTest.php
@@ -14,7 +14,7 @@ class ItemHalJsonCookieTest extends ItemHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonTestBase.php b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonTestBase.php
index c786b7b181..5c5120b945 100644
--- a/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonTestBase.php
+++ b/core/modules/aggregator/tests/src/Functional/Hal/ItemHalJsonTestBase.php
@@ -18,7 +18,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/ImportOpmlTest.php b/core/modules/aggregator/tests/src/Functional/ImportOpmlTest.php
index 2500b9ebb5..68543bf008 100644
--- a/core/modules/aggregator/tests/src/Functional/ImportOpmlTest.php
+++ b/core/modules/aggregator/tests/src/Functional/ImportOpmlTest.php
@@ -14,7 +14,7 @@ class ImportOpmlTest extends AggregatorTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'help'];
+  protected static $modules = ['block', 'help'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/ItemCacheTagsTest.php b/core/modules/aggregator/tests/src/Functional/ItemCacheTagsTest.php
index edd2ac32a9..6d852db838 100644
--- a/core/modules/aggregator/tests/src/Functional/ItemCacheTagsTest.php
+++ b/core/modules/aggregator/tests/src/Functional/ItemCacheTagsTest.php
@@ -19,7 +19,7 @@ class ItemCacheTagsTest extends EntityCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/FeedJsonBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Rest/FeedJsonBasicAuthTest.php
index e918ab9819..e10df2f042 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/FeedJsonBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/FeedJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FeedJsonBasicAuthTest extends FeedResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php b/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php
index fefa75e1ff..f62305075d 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/FeedXmlBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Rest/FeedXmlBasicAuthTest.php
index 450cc49eff..ca2d964f7e 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/FeedXmlBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/FeedXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class FeedXmlBasicAuthTest extends FeedResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/ItemJsonBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Rest/ItemJsonBasicAuthTest.php
index 15f800d138..f69c51b045 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/ItemJsonBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/ItemJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ItemJsonBasicAuthTest extends ItemResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/ItemResourceTestBase.php b/core/modules/aggregator/tests/src/Functional/Rest/ItemResourceTestBase.php
index c7163e098a..761f8de51e 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/ItemResourceTestBase.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/ItemResourceTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Functional/Rest/ItemXmlBasicAuthTest.php b/core/modules/aggregator/tests/src/Functional/Rest/ItemXmlBasicAuthTest.php
index 438a4233ca..f868a21dfa 100644
--- a/core/modules/aggregator/tests/src/Functional/Rest/ItemXmlBasicAuthTest.php
+++ b/core/modules/aggregator/tests/src/Functional/Rest/ItemXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ItemXmlBasicAuthTest extends ItemResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/AggregatorTitleTest.php b/core/modules/aggregator/tests/src/Kernel/AggregatorTitleTest.php
index 4493c5c8d7..374a2c10fb 100644
--- a/core/modules/aggregator/tests/src/Kernel/AggregatorTitleTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/AggregatorTitleTest.php
@@ -18,7 +18,7 @@ class AggregatorTitleTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'field', 'options', 'aggregator', 'system'];
+  protected static $modules = ['file', 'field', 'options', 'aggregator', 'system'];
 
   /**
    * The field name that is tested.
diff --git a/core/modules/aggregator/tests/src/Kernel/FeedValidationTest.php b/core/modules/aggregator/tests/src/Kernel/FeedValidationTest.php
index d8804dd9c3..b3e10e4a03 100644
--- a/core/modules/aggregator/tests/src/Kernel/FeedValidationTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/FeedValidationTest.php
@@ -17,7 +17,7 @@ class FeedValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['aggregator', 'options'];
+  protected static $modules = ['aggregator', 'options'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/ItemWithoutFeedTest.php b/core/modules/aggregator/tests/src/Kernel/ItemWithoutFeedTest.php
index e44bd4f3cd..705c4b6b2a 100644
--- a/core/modules/aggregator/tests/src/Kernel/ItemWithoutFeedTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/ItemWithoutFeedTest.php
@@ -15,7 +15,7 @@ class ItemWithoutFeedTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'options'];
+  protected static $modules = ['aggregator', 'options'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php
index 8de1487d0c..f85c957e0b 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php
@@ -17,7 +17,7 @@ class MigrateAggregatorStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorConfigsTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorConfigsTest.php
index 280a103db8..a9a4355ab4 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorConfigsTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateAggregatorConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorFeedTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorFeedTest.php
index 9dac60faa8..eef5ba448b 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorFeedTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorFeedTest.php
@@ -15,7 +15,7 @@ class MigrateAggregatorFeedTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorItemTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorItemTest.php
index 5343d1e2de..d14846c7c9 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorItemTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d6/MigrateAggregatorItemTest.php
@@ -15,7 +15,7 @@ class MigrateAggregatorItemTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorFeedTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorFeedTest.php
index fd208238c7..e4dbe34aeb 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorFeedTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorFeedTest.php
@@ -15,7 +15,7 @@ class MigrateAggregatorFeedTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorItemTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorItemTest.php
index 83e59d9707..8dde35b298 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorItemTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorItemTest.php
@@ -15,7 +15,7 @@ class MigrateAggregatorItemTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorSettingsTest.php b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorSettingsTest.php
index 0fa8f63597..9e2eb36545 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorSettingsTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/d7/MigrateAggregatorSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateAggregatorSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorFeedTest.php b/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorFeedTest.php
index d41f4f4b38..67fe136808 100644
--- a/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorFeedTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorFeedTest.php
@@ -15,7 +15,7 @@ class AggregatorFeedTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'migrate_drupal'];
+  protected static $modules = ['aggregator', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorItemTest.php b/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorItemTest.php
index 09101f7cd4..ea9206a44b 100644
--- a/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorItemTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Plugin/migrate/source/AggregatorItemTest.php
@@ -15,7 +15,7 @@ class AggregatorItemTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'migrate_drupal'];
+  protected static $modules = ['aggregator', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Views/AggregatorFeedViewsFieldAccessTest.php b/core/modules/aggregator/tests/src/Kernel/Views/AggregatorFeedViewsFieldAccessTest.php
index d0ca46ead9..2d5a5f53a9 100644
--- a/core/modules/aggregator/tests/src/Kernel/Views/AggregatorFeedViewsFieldAccessTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Views/AggregatorFeedViewsFieldAccessTest.php
@@ -15,7 +15,7 @@ class AggregatorFeedViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'entity_test', 'options'];
+  protected static $modules = ['aggregator', 'entity_test', 'options'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Views/AggregatorItemViewsFieldAccessTest.php b/core/modules/aggregator/tests/src/Kernel/Views/AggregatorItemViewsFieldAccessTest.php
index a095d3c42f..a016467812 100644
--- a/core/modules/aggregator/tests/src/Kernel/Views/AggregatorItemViewsFieldAccessTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Views/AggregatorItemViewsFieldAccessTest.php
@@ -16,7 +16,7 @@ class AggregatorItemViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'entity_test', 'options'];
+  protected static $modules = ['aggregator', 'entity_test', 'options'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/tests/src/Kernel/Views/IntegrationTest.php b/core/modules/aggregator/tests/src/Kernel/Views/IntegrationTest.php
index 39f57b2518..be9d149c14 100644
--- a/core/modules/aggregator/tests/src/Kernel/Views/IntegrationTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Views/IntegrationTest.php
@@ -21,7 +21,7 @@ class IntegrationTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['aggregator', 'aggregator_test_views', 'system', 'field', 'options', 'user'];
+  protected static $modules = ['aggregator', 'aggregator_test_views', 'system', 'field', 'options', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/ban/tests/src/Functional/IpAddressBlockingTest.php b/core/modules/ban/tests/src/Functional/IpAddressBlockingTest.php
index 778f3dba97..92ebcdf6ff 100644
--- a/core/modules/ban/tests/src/Functional/IpAddressBlockingTest.php
+++ b/core/modules/ban/tests/src/Functional/IpAddressBlockingTest.php
@@ -18,7 +18,7 @@ class IpAddressBlockingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['ban'];
+  protected static $modules = ['ban'];
 
   /**
    * Tests various user input to confirm correct validation and saving of data.
diff --git a/core/modules/ban/tests/src/Kernel/Migrate/d7/MigrateBlockedIPsTest.php b/core/modules/ban/tests/src/Kernel/Migrate/d7/MigrateBlockedIPsTest.php
index 48f35a7e11..d673ec5589 100644
--- a/core/modules/ban/tests/src/Kernel/Migrate/d7/MigrateBlockedIPsTest.php
+++ b/core/modules/ban/tests/src/Kernel/Migrate/d7/MigrateBlockedIPsTest.php
@@ -19,7 +19,7 @@ class MigrateBlockedIPsTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = ['ban'];
+  protected static $modules = ['ban'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php b/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php
index 2ce7820a7d..80adf4ec54 100644
--- a/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php
+++ b/core/modules/ban/tests/src/Kernel/Plugin/migrate/source/d7/BlockedIpsTest.php
@@ -15,7 +15,7 @@ class BlockedIpsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ban', 'migrate_drupal'];
+  protected static $modules = ['ban', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php b/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php
index ed13ea5d38..39adeb1b03 100644
--- a/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php
+++ b/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php
@@ -23,7 +23,7 @@ class BasicAuthTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['basic_auth', 'router_test', 'locale', 'basic_auth_test'];
+  protected static $modules = ['basic_auth', 'router_test', 'locale', 'basic_auth_test'];
 
   /**
    * Test http basic authentication.
diff --git a/core/modules/big_pipe/tests/src/Functional/BigPipeTest.php b/core/modules/big_pipe/tests/src/Functional/BigPipeTest.php
index 8b6327cadb..3b477b072c 100644
--- a/core/modules/big_pipe/tests/src/Functional/BigPipeTest.php
+++ b/core/modules/big_pipe/tests/src/Functional/BigPipeTest.php
@@ -30,7 +30,7 @@ class BigPipeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['big_pipe', 'big_pipe_test', 'dblog'];
+  protected static $modules = ['big_pipe', 'big_pipe_test', 'dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/big_pipe/tests/src/FunctionalJavascript/BigPipeRegressionTest.php b/core/modules/big_pipe/tests/src/FunctionalJavascript/BigPipeRegressionTest.php
index f4cd5108bf..4abd9dc60a 100644
--- a/core/modules/big_pipe/tests/src/FunctionalJavascript/BigPipeRegressionTest.php
+++ b/core/modules/big_pipe/tests/src/FunctionalJavascript/BigPipeRegressionTest.php
@@ -29,7 +29,7 @@ class BigPipeRegressionTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'big_pipe',
     'big_pipe_regression_test',
   ];
diff --git a/core/modules/block/src/Tests/BlockTestBase.php b/core/modules/block/src/Tests/BlockTestBase.php
index 7397a47053..8419db75a5 100644
--- a/core/modules/block/src/Tests/BlockTestBase.php
+++ b/core/modules/block/src/Tests/BlockTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'filter', 'test_page_test', 'help', 'block_test'];
+  protected static $modules = ['block', 'filter', 'test_page_test', 'help', 'block_test'];
 
   /**
    * A list of theme regions to test.
diff --git a/core/modules/block/tests/src/Functional/BlockAdminThemeTest.php b/core/modules/block/tests/src/Functional/BlockAdminThemeTest.php
index 88f35e4b09..3189e67399 100644
--- a/core/modules/block/tests/src/Functional/BlockAdminThemeTest.php
+++ b/core/modules/block/tests/src/Functional/BlockAdminThemeTest.php
@@ -16,7 +16,7 @@ class BlockAdminThemeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'contextual'];
+  protected static $modules = ['block', 'contextual'];
 
   /**
    * Check for the accessibility of the admin theme on the block admin page.
diff --git a/core/modules/block/tests/src/Functional/BlockCacheTest.php b/core/modules/block/tests/src/Functional/BlockCacheTest.php
index e5bb360e3e..6413e50017 100644
--- a/core/modules/block/tests/src/Functional/BlockCacheTest.php
+++ b/core/modules/block/tests/src/Functional/BlockCacheTest.php
@@ -17,7 +17,7 @@ class BlockCacheTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'test_page_test'];
+  protected static $modules = ['block', 'block_test', 'test_page_test'];
 
   /**
    * A user with permission to create and edit books and to administer blocks.
diff --git a/core/modules/block/tests/src/Functional/BlockDemoTest.php b/core/modules/block/tests/src/Functional/BlockDemoTest.php
index 884b587a11..5977531130 100644
--- a/core/modules/block/tests/src/Functional/BlockDemoTest.php
+++ b/core/modules/block/tests/src/Functional/BlockDemoTest.php
@@ -16,7 +16,7 @@ class BlockDemoTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Check for the accessibility of the admin block demo page.
diff --git a/core/modules/block/tests/src/Functional/BlockFormInBlockTest.php b/core/modules/block/tests/src/Functional/BlockFormInBlockTest.php
index c0e7f58926..ea5702b83d 100644
--- a/core/modules/block/tests/src/Functional/BlockFormInBlockTest.php
+++ b/core/modules/block/tests/src/Functional/BlockFormInBlockTest.php
@@ -17,7 +17,7 @@ class BlockFormInBlockTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'test_page_test'];
+  protected static $modules = ['block', 'block_test', 'test_page_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php b/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
index c51551521a..4b3244f0ba 100644
--- a/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
+++ b/core/modules/block/tests/src/Functional/BlockHiddenRegionTest.php
@@ -22,7 +22,7 @@ class BlockHiddenRegionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'search'];
+  protected static $modules = ['block', 'block_test', 'search'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockHookOperationTest.php b/core/modules/block/tests/src/Functional/BlockHookOperationTest.php
index 23b1f0ce5f..a2bdd5c545 100644
--- a/core/modules/block/tests/src/Functional/BlockHookOperationTest.php
+++ b/core/modules/block/tests/src/Functional/BlockHookOperationTest.php
@@ -16,7 +16,7 @@ class BlockHookOperationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'entity_test'];
+  protected static $modules = ['block', 'entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockHtmlTest.php b/core/modules/block/tests/src/Functional/BlockHtmlTest.php
index 5f9afe916f..b2426e4056 100644
--- a/core/modules/block/tests/src/Functional/BlockHtmlTest.php
+++ b/core/modules/block/tests/src/Functional/BlockHtmlTest.php
@@ -16,7 +16,7 @@ class BlockHtmlTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test'];
+  protected static $modules = ['block', 'block_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php b/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
index fe8cdcb56a..c7425fa424 100644
--- a/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
+++ b/core/modules/block/tests/src/Functional/BlockInvalidRegionTest.php
@@ -18,7 +18,7 @@ class BlockInvalidRegionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test'];
+  protected static $modules = ['block', 'block_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php b/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php
index 9ca2b71863..9f732ad7c7 100644
--- a/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php
+++ b/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php
@@ -17,7 +17,7 @@ class BlockLanguageCacheTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'language', 'menu_ui'];
+  protected static $modules = ['block', 'language', 'menu_ui'];
 
   /**
    * List of langcodes.
diff --git a/core/modules/block/tests/src/Functional/BlockLanguageTest.php b/core/modules/block/tests/src/Functional/BlockLanguageTest.php
index 8f963e17e6..d7d7e60c9e 100644
--- a/core/modules/block/tests/src/Functional/BlockLanguageTest.php
+++ b/core/modules/block/tests/src/Functional/BlockLanguageTest.php
@@ -23,7 +23,7 @@ class BlockLanguageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'block', 'content_translation'];
+  protected static $modules = ['language', 'block', 'content_translation'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockRenderOrderTest.php b/core/modules/block/tests/src/Functional/BlockRenderOrderTest.php
index 2fd1ab8925..e0668606e8 100644
--- a/core/modules/block/tests/src/Functional/BlockRenderOrderTest.php
+++ b/core/modules/block/tests/src/Functional/BlockRenderOrderTest.php
@@ -17,7 +17,7 @@ class BlockRenderOrderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block'];
+  protected static $modules = ['node', 'block'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/block/tests/src/Functional/BlockSystemBrandingTest.php b/core/modules/block/tests/src/Functional/BlockSystemBrandingTest.php
index 89ce0c4b45..27cf5bc79a 100644
--- a/core/modules/block/tests/src/Functional/BlockSystemBrandingTest.php
+++ b/core/modules/block/tests/src/Functional/BlockSystemBrandingTest.php
@@ -14,7 +14,7 @@ class BlockSystemBrandingTest extends BlockTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'system'];
+  protected static $modules = ['block', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/BlockTemplateSuggestionsTest.php b/core/modules/block/tests/src/Functional/BlockTemplateSuggestionsTest.php
index fd4fd5138c..fe0f7bbd09 100644
--- a/core/modules/block/tests/src/Functional/BlockTemplateSuggestionsTest.php
+++ b/core/modules/block/tests/src/Functional/BlockTemplateSuggestionsTest.php
@@ -17,7 +17,7 @@ class BlockTemplateSuggestionsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Tests template suggestions from block_theme_suggestions_block().
diff --git a/core/modules/block/tests/src/Functional/BlockTestBase.php b/core/modules/block/tests/src/Functional/BlockTestBase.php
index e1ccd1a365..725c04d6fc 100644
--- a/core/modules/block/tests/src/Functional/BlockTestBase.php
+++ b/core/modules/block/tests/src/Functional/BlockTestBase.php
@@ -15,7 +15,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'filter', 'test_page_test', 'help', 'block_test'];
+  protected static $modules = ['block', 'filter', 'test_page_test', 'help', 'block_test'];
 
   /**
    * A list of theme regions to test.
diff --git a/core/modules/block/tests/src/Functional/BlockUiTest.php b/core/modules/block/tests/src/Functional/BlockUiTest.php
index e6c187544e..b5e818ef9d 100644
--- a/core/modules/block/tests/src/Functional/BlockUiTest.php
+++ b/core/modules/block/tests/src/Functional/BlockUiTest.php
@@ -17,7 +17,7 @@ class BlockUiTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'help', 'condition_test'];
+  protected static $modules = ['block', 'block_test', 'help', 'condition_test'];
 
   protected $regions;
 
diff --git a/core/modules/block/tests/src/Functional/BlockXssTest.php b/core/modules/block/tests/src/Functional/BlockXssTest.php
index 3e661d775d..7eea08103d 100644
--- a/core/modules/block/tests/src/Functional/BlockXssTest.php
+++ b/core/modules/block/tests/src/Functional/BlockXssTest.php
@@ -21,7 +21,7 @@ class BlockXssTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'menu_ui', 'views'];
+  protected static $modules = ['block', 'block_content', 'menu_ui', 'views'];
 
   /**
    * Tests that nothing is escaped other than the blocks explicitly tested.
diff --git a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonAnonTest.php b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonAnonTest.php
index 3069667c2d..ca140d47a8 100644
--- a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonAnonTest.php
+++ b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class BlockHalJsonAnonTest extends BlockResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonBasicAuthTest.php b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonBasicAuthTest.php
index f95f6d732b..a574ba776a 100644
--- a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonBasicAuthTest.php
+++ b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class BlockHalJsonBasicAuthTest extends BlockResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonCookieTest.php b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonCookieTest.php
index 87df9ff580..f1d4df9832 100644
--- a/core/modules/block/tests/src/Functional/Hal/BlockHalJsonCookieTest.php
+++ b/core/modules/block/tests/src/Functional/Hal/BlockHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class BlockHalJsonCookieTest extends BlockResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/NewDefaultThemeBlocksTest.php b/core/modules/block/tests/src/Functional/NewDefaultThemeBlocksTest.php
index adc7da3f1f..b3353aedb9 100644
--- a/core/modules/block/tests/src/Functional/NewDefaultThemeBlocksTest.php
+++ b/core/modules/block/tests/src/Functional/NewDefaultThemeBlocksTest.php
@@ -16,7 +16,7 @@ class NewDefaultThemeBlocksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Check the enabled Bartik blocks are correctly copied over.
diff --git a/core/modules/block/tests/src/Functional/NonDefaultBlockAdminTest.php b/core/modules/block/tests/src/Functional/NonDefaultBlockAdminTest.php
index 7b7927de20..1e9bed972c 100644
--- a/core/modules/block/tests/src/Functional/NonDefaultBlockAdminTest.php
+++ b/core/modules/block/tests/src/Functional/NonDefaultBlockAdminTest.php
@@ -16,7 +16,7 @@ class NonDefaultBlockAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Rest/BlockJsonBasicAuthTest.php b/core/modules/block/tests/src/Functional/Rest/BlockJsonBasicAuthTest.php
index 9c2a272826..819a5fbfd9 100644
--- a/core/modules/block/tests/src/Functional/Rest/BlockJsonBasicAuthTest.php
+++ b/core/modules/block/tests/src/Functional/Rest/BlockJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class BlockJsonBasicAuthTest extends BlockResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Rest/BlockResourceTestBase.php b/core/modules/block/tests/src/Functional/Rest/BlockResourceTestBase.php
index 998690caa8..bfb09c5f74 100644
--- a/core/modules/block/tests/src/Functional/Rest/BlockResourceTestBase.php
+++ b/core/modules/block/tests/src/Functional/Rest/BlockResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Rest/BlockXmlBasicAuthTest.php b/core/modules/block/tests/src/Functional/Rest/BlockXmlBasicAuthTest.php
index 2b720d1d9f..60631cdb2a 100644
--- a/core/modules/block/tests/src/Functional/Rest/BlockXmlBasicAuthTest.php
+++ b/core/modules/block/tests/src/Functional/Rest/BlockXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class BlockXmlBasicAuthTest extends BlockResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php b/core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
index 0a18d7fa0f..fd3a1d1da5 100644
--- a/core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
+++ b/core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
@@ -28,7 +28,7 @@ class DisplayBlockTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block_test_views', 'test_page_test', 'contextual', 'views_ui'];
+  protected static $modules = ['node', 'block_test_views', 'test_page_test', 'contextual', 'views_ui'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/block/tests/src/FunctionalJavascript/BlockFilterTest.php b/core/modules/block/tests/src/FunctionalJavascript/BlockFilterTest.php
index e9ecc06526..b083bc3c57 100644
--- a/core/modules/block/tests/src/FunctionalJavascript/BlockFilterTest.php
+++ b/core/modules/block/tests/src/FunctionalJavascript/BlockFilterTest.php
@@ -15,7 +15,7 @@ class BlockFilterTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'block'];
+  protected static $modules = ['user', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Kernel/BlockConfigSchemaTest.php b/core/modules/block/tests/src/Kernel/BlockConfigSchemaTest.php
index 2bf41e0f4c..cfd9a4680c 100644
--- a/core/modules/block/tests/src/Kernel/BlockConfigSchemaTest.php
+++ b/core/modules/block/tests/src/Kernel/BlockConfigSchemaTest.php
@@ -18,7 +18,7 @@ class BlockConfigSchemaTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'aggregator',
     'book',
diff --git a/core/modules/block/tests/src/Kernel/BlockInterfaceTest.php b/core/modules/block/tests/src/Kernel/BlockInterfaceTest.php
index 48d63a302d..6e1a4d2545 100644
--- a/core/modules/block/tests/src/Kernel/BlockInterfaceTest.php
+++ b/core/modules/block/tests/src/Kernel/BlockInterfaceTest.php
@@ -13,7 +13,7 @@
  */
 class BlockInterfaceTest extends KernelTestBase {
 
-  public static $modules = ['system', 'block', 'block_test', 'user'];
+  protected static $modules = ['system', 'block', 'block_test', 'user'];
 
   /**
    * Test configuration and subsequent form() and build() method calls.
diff --git a/core/modules/block/tests/src/Kernel/BlockRebuildTest.php b/core/modules/block/tests/src/Kernel/BlockRebuildTest.php
index 2443c21052..3cd63dff1d 100644
--- a/core/modules/block/tests/src/Kernel/BlockRebuildTest.php
+++ b/core/modules/block/tests/src/Kernel/BlockRebuildTest.php
@@ -19,7 +19,7 @@ class BlockRebuildTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'system'];
+  protected static $modules = ['block', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Kernel/BlockStorageUnitTest.php b/core/modules/block/tests/src/Kernel/BlockStorageUnitTest.php
index cfe9d1b0d8..59ce2dbe98 100644
--- a/core/modules/block/tests/src/Kernel/BlockStorageUnitTest.php
+++ b/core/modules/block/tests/src/Kernel/BlockStorageUnitTest.php
@@ -21,7 +21,7 @@ class BlockStorageUnitTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'system'];
+  protected static $modules = ['block', 'block_test', 'system'];
 
   /**
    * The block storage.
diff --git a/core/modules/block/tests/src/Kernel/BlockViewBuilderTest.php b/core/modules/block/tests/src/Kernel/BlockViewBuilderTest.php
index 71c4f55b8d..05164de28c 100644
--- a/core/modules/block/tests/src/Kernel/BlockViewBuilderTest.php
+++ b/core/modules/block/tests/src/Kernel/BlockViewBuilderTest.php
@@ -20,7 +20,7 @@ class BlockViewBuilderTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'system', 'user'];
+  protected static $modules = ['block', 'block_test', 'system', 'user'];
 
   /**
    * The block being tested.
diff --git a/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockContentTranslationTest.php b/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockContentTranslationTest.php
index 4078782143..515e5eeb4a 100644
--- a/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockContentTranslationTest.php
+++ b/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockContentTranslationTest.php
@@ -14,7 +14,7 @@ class MigrateBlockContentTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'aggregator',
     'book',
     'block',
diff --git a/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockTest.php b/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockTest.php
index e0876fd1e4..9b499b820f 100644
--- a/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockTest.php
+++ b/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockTest.php
@@ -15,7 +15,7 @@ class MigrateBlockTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'views',
     'comment',
diff --git a/core/modules/block/tests/src/Kernel/Migrate/d7/MigrateBlockTest.php b/core/modules/block/tests/src/Kernel/Migrate/d7/MigrateBlockTest.php
index 6f07dc9c21..8028cbc0b9 100644
--- a/core/modules/block/tests/src/Kernel/Migrate/d7/MigrateBlockTest.php
+++ b/core/modules/block/tests/src/Kernel/Migrate/d7/MigrateBlockTest.php
@@ -16,7 +16,7 @@ class MigrateBlockTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'views',
     'comment',
diff --git a/core/modules/block/tests/src/Kernel/Plugin/migrate/source/BlockTest.php b/core/modules/block/tests/src/Kernel/Plugin/migrate/source/BlockTest.php
index 66c2679bb0..b0f507e126 100644
--- a/core/modules/block/tests/src/Kernel/Plugin/migrate/source/BlockTest.php
+++ b/core/modules/block/tests/src/Kernel/Plugin/migrate/source/BlockTest.php
@@ -15,7 +15,7 @@ class BlockTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'migrate_drupal'];
+  protected static $modules = ['block', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block/tests/src/Kernel/Plugin/migrate/source/d6/BlockTranslationTest.php b/core/modules/block/tests/src/Kernel/Plugin/migrate/source/d6/BlockTranslationTest.php
index 445f32cec5..18dd804135 100644
--- a/core/modules/block/tests/src/Kernel/Plugin/migrate/source/d6/BlockTranslationTest.php
+++ b/core/modules/block/tests/src/Kernel/Plugin/migrate/source/d6/BlockTranslationTest.php
@@ -16,7 +16,7 @@ class BlockTranslationTest extends BlockTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/src/Tests/BlockContentTestBase.php b/core/modules/block_content/src/Tests/BlockContentTestBase.php
index a60ab91d4b..b3a3b8d476 100644
--- a/core/modules/block_content/src/Tests/BlockContentTestBase.php
+++ b/core/modules/block_content/src/Tests/BlockContentTestBase.php
@@ -42,7 +42,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content'];
+  protected static $modules = ['block', 'block_content'];
 
   /**
    * Whether or not to auto-create the basic block type during setup.
diff --git a/core/modules/block_content/src/Tests/Views/BlockContentTestBase.php b/core/modules/block_content/src/Tests/Views/BlockContentTestBase.php
index 0e3fbfeeb0..24b7770f04 100644
--- a/core/modules/block_content/src/Tests/Views/BlockContentTestBase.php
+++ b/core/modules/block_content/src/Tests/Views/BlockContentTestBase.php
@@ -39,7 +39,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'block_content_test_views'];
+  protected static $modules = ['block', 'block_content', 'block_content_test_views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentCacheTagsTest.php b/core/modules/block_content/tests/src/Functional/BlockContentCacheTagsTest.php
index ea5dd2873d..d226273ae0 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentCacheTagsTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentCacheTagsTest.php
@@ -20,7 +20,7 @@ class BlockContentCacheTagsTest extends EntityCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
index e4e1a48ac8..0920781c06 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentContextualLinksTest.php
@@ -12,7 +12,7 @@ class BlockContentContextualLinksTest extends BlockContentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
   ];
 
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php b/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
index 46768d694b..1f3576493a 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
@@ -20,7 +20,7 @@ class BlockContentCreationTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block_content_test', 'dblog', 'field_ui'];
+  protected static $modules = ['block_content_test', 'dblog', 'field_ui'];
 
   /**
    * Permissions to grant admin user.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentListTest.php b/core/modules/block_content/tests/src/Functional/BlockContentListTest.php
index 8919c05d00..cf665bffae 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentListTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentListTest.php
@@ -20,7 +20,7 @@ class BlockContentListTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'config_translation'];
+  protected static $modules = ['block', 'block_content', 'config_translation'];
 
   /**
    * Tests the custom block listing page.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php b/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php
index f9cf29eb77..c89ef37ca5 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php
@@ -18,7 +18,7 @@ class BlockContentListViewsTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'config_translation', 'views'];
+  protected static $modules = ['block', 'block_content', 'config_translation', 'views'];
 
   /**
    * Tests the custom block listing page.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentPageViewTest.php b/core/modules/block_content/tests/src/Functional/BlockContentPageViewTest.php
index 355faf1f0f..5e773e9035 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentPageViewTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentPageViewTest.php
@@ -14,7 +14,7 @@ class BlockContentPageViewTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block_content_test'];
+  protected static $modules = ['block_content_test'];
 
   /**
    * Checks block edit and fallback functionality.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentSaveTest.php b/core/modules/block_content/tests/src/Functional/BlockContentSaveTest.php
index fe730e8a0c..70377c4bbd 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentSaveTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentSaveTest.php
@@ -16,7 +16,7 @@ class BlockContentSaveTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block_content_test'];
+  protected static $modules = ['block_content_test'];
 
   /**
    * Sets the test up.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php b/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php
index c8c32fdacf..50bf4fc8f1 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php
@@ -39,7 +39,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content'];
+  protected static $modules = ['block', 'block_content'];
 
   /**
    * Whether or not to auto-create the basic block type during setup.
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php b/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php
index 6fc5f1af01..1652bd3e59 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php
@@ -18,7 +18,7 @@ class BlockContentTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'block',
diff --git a/core/modules/block_content/tests/src/Functional/BlockContentTypeTest.php b/core/modules/block_content/tests/src/Functional/BlockContentTypeTest.php
index b707c83a92..9303a8f73a 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentTypeTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentTypeTest.php
@@ -20,7 +20,7 @@ class BlockContentTypeTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui'];
+  protected static $modules = ['field_ui'];
 
   /**
    * Permissions to grant admin user.
diff --git a/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonAnonTest.php b/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonAnonTest.php
index 33c1108d24..ce9e410748 100644
--- a/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonAnonTest.php
+++ b/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class BlockContentHalJsonAnonTest extends BlockContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonBasicAuthTest.php
index b9b262e9be..bec66f1df1 100644
--- a/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Hal/BlockContentHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class BlockContentHalJsonBasicAuthTest extends BlockContentHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonAnonTest.php b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonAnonTest.php
index 3bfff1068a..67a1e94328 100644
--- a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonAnonTest.php
+++ b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class BlockContentTypeHalJsonAnonTest extends BlockContentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonBasicAuthTest.php
index 6112c2b60a..8bcabcf517 100644
--- a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class BlockContentTypeHalJsonBasicAuthTest extends BlockContentTypeResourceTestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonCookieTest.php b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonCookieTest.php
index 889d775cde..970cc73722 100644
--- a/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonCookieTest.php
+++ b/core/modules/block_content/tests/src/Functional/Hal/BlockContentTypeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class BlockContentTypeHalJsonCookieTest extends BlockContentTypeResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentJsonBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentJsonBasicAuthTest.php
index 63bf314eb5..44e7657efd 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentJsonBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class BlockContentJsonBasicAuthTest extends BlockContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentResourceTestBase.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentResourceTestBase.php
index 4a3ac11f4c..e74f4e2f32 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentResourceTestBase.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentResourceTestBase.php
@@ -18,7 +18,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeJsonBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeJsonBasicAuthTest.php
index a993d1f1bd..7884a4ff46 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeJsonBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class BlockContentTypeJsonBasicAuthTest extends BlockContentTypeResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeResourceTestBase.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeResourceTestBase.php
index 13d6ed2d00..46fe436be6 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeResourceTestBase.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeXmlBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeXmlBasicAuthTest.php
index a878c7d5b3..1a402fbd4d 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeXmlBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentTypeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class BlockContentTypeXmlBasicAuthTest extends BlockContentTypeResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Rest/BlockContentXmlBasicAuthTest.php b/core/modules/block_content/tests/src/Functional/Rest/BlockContentXmlBasicAuthTest.php
index 199abea08d..73dd5c90e0 100644
--- a/core/modules/block_content/tests/src/Functional/Rest/BlockContentXmlBasicAuthTest.php
+++ b/core/modules/block_content/tests/src/Functional/Rest/BlockContentXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class BlockContentXmlBasicAuthTest extends BlockContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php b/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
index 8f87ccaccc..c85816d561 100644
--- a/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
+++ b/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
@@ -18,7 +18,7 @@ class UnpublishedBlockTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * Tests unpublishing of block_content entities.
diff --git a/core/modules/block_content/tests/src/Functional/Views/BlockContentFieldFilterTest.php b/core/modules/block_content/tests/src/Functional/Views/BlockContentFieldFilterTest.php
index a77c2e1b29..70c7f07fc5 100644
--- a/core/modules/block_content/tests/src/Functional/Views/BlockContentFieldFilterTest.php
+++ b/core/modules/block_content/tests/src/Functional/Views/BlockContentFieldFilterTest.php
@@ -15,7 +15,7 @@ class BlockContentFieldFilterTest extends BlockContentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/block_content/tests/src/Functional/Views/BlockContentRedirectTest.php b/core/modules/block_content/tests/src/Functional/Views/BlockContentRedirectTest.php
index 10ce140e96..d283a1bd55 100644
--- a/core/modules/block_content/tests/src/Functional/Views/BlockContentRedirectTest.php
+++ b/core/modules/block_content/tests/src/Functional/Views/BlockContentRedirectTest.php
@@ -21,7 +21,7 @@ class BlockContentRedirectTest extends BlockContentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'views'];
+  protected static $modules = ['block', 'block_content', 'views'];
 
   /**
    * Tests the redirect destination when editing block content.
diff --git a/core/modules/block_content/tests/src/Functional/Views/BlockContentTestBase.php b/core/modules/block_content/tests/src/Functional/Views/BlockContentTestBase.php
index dd14a4266c..c3cd0deac8 100644
--- a/core/modules/block_content/tests/src/Functional/Views/BlockContentTestBase.php
+++ b/core/modules/block_content/tests/src/Functional/Views/BlockContentTestBase.php
@@ -34,7 +34,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'block_content', 'block_content_test_views'];
+  protected static $modules = ['block', 'block_content', 'block_content_test_views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/block_content/tests/src/Functional/Views/BlockContentWizardTest.php b/core/modules/block_content/tests/src/Functional/Views/BlockContentWizardTest.php
index 2c59e5c50f..5275605c2d 100644
--- a/core/modules/block_content/tests/src/Functional/Views/BlockContentWizardTest.php
+++ b/core/modules/block_content/tests/src/Functional/Views/BlockContentWizardTest.php
@@ -14,7 +14,7 @@ class BlockContentWizardTest extends BlockContentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content', 'views_ui'];
+  protected static $modules = ['block_content', 'views_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Functional/Views/RevisionRelationshipsTest.php b/core/modules/block_content/tests/src/Functional/Views/RevisionRelationshipsTest.php
index 0ccebd2a9f..f5240c41f0 100644
--- a/core/modules/block_content/tests/src/Functional/Views/RevisionRelationshipsTest.php
+++ b/core/modules/block_content/tests/src/Functional/Views/RevisionRelationshipsTest.php
@@ -20,7 +20,7 @@ class RevisionRelationshipsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['block_content' , 'block_content_test_views'];
+  protected static $modules = ['block_content' , 'block_content_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentAccessHandlerTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentAccessHandlerTest.php
index 64b524d80b..45510ed859 100644
--- a/core/modules/block_content/tests/src/Kernel/BlockContentAccessHandlerTest.php
+++ b/core/modules/block_content/tests/src/Kernel/BlockContentAccessHandlerTest.php
@@ -23,7 +23,7 @@ class BlockContentAccessHandlerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'block_content',
     'system',
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentDeletionTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentDeletionTest.php
index e54b2d3d4a..2274750205 100644
--- a/core/modules/block_content/tests/src/Kernel/BlockContentDeletionTest.php
+++ b/core/modules/block_content/tests/src/Kernel/BlockContentDeletionTest.php
@@ -17,7 +17,7 @@ class BlockContentDeletionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'block_content', 'system', 'user'];
+  protected static $modules = ['block', 'block_content', 'system', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentDeriverTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentDeriverTest.php
index d08d86f25f..cfec70a305 100644
--- a/core/modules/block_content/tests/src/Kernel/BlockContentDeriverTest.php
+++ b/core/modules/block_content/tests/src/Kernel/BlockContentDeriverTest.php
@@ -17,7 +17,7 @@ class BlockContentDeriverTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'block_content', 'system', 'user'];
+  protected static $modules = ['block', 'block_content', 'system', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php
index e593336fa3..f6dd9dec6b 100644
--- a/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php
+++ b/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php
@@ -19,7 +19,7 @@ class BlockContentEntityReferenceSelectionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'block_content',
     'block_content_test',
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentBodyFieldTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentBodyFieldTest.php
index 7d343738c9..d09a26bde1 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentBodyFieldTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentBodyFieldTest.php
@@ -15,7 +15,7 @@
  */
 class MigrateBlockContentBodyFieldTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['block', 'block_content', 'filter', 'text'];
+  protected static $modules = ['block', 'block_content', 'filter', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityDisplayTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityDisplayTest.php
index 5eb9e413d9..1cd4b35fee 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityDisplayTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateBlockContentEntityDisplayTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'block_content', 'filter', 'text'];
+  protected static $modules = ['block', 'block_content', 'filter', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityFormDisplayTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityFormDisplayTest.php
index 8fed905848..314e41298b 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityFormDisplayTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentEntityFormDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateBlockContentEntityFormDisplayTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'block_content', 'filter', 'text'];
+  protected static $modules = ['block', 'block_content', 'filter', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentStubTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentStubTest.php
index 1958039acb..a6356edc7e 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentStubTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentStubTest.php
@@ -19,7 +19,7 @@ class MigrateBlockContentStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentTypeTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentTypeTest.php
index 4accc2040b..e8ab991088 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentTypeTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentTypeTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateBlockContentTypeTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['block', 'block_content', 'filter', 'text'];
+  protected static $modules = ['block', 'block_content', 'filter', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateBlockContentTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateBlockContentTest.php
index 87e6fac893..22e37e4de8 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateBlockContentTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateBlockContentTest.php
@@ -15,7 +15,7 @@ class MigrateBlockContentTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'block_content'];
+  protected static $modules = ['block', 'block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateCustomBlockContentTranslationTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateCustomBlockContentTranslationTest.php
index 2847e35d5e..45f0c88ba6 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateCustomBlockContentTranslationTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/d6/MigrateCustomBlockContentTranslationTest.php
@@ -15,7 +15,7 @@ class MigrateCustomBlockContentTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block_content',
     'content_translation',
     'language',
diff --git a/core/modules/block_content/tests/src/Kernel/Migrate/d7/MigrateCustomBlockTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/d7/MigrateCustomBlockTest.php
index 706a7ccf05..edab6765b8 100644
--- a/core/modules/block_content/tests/src/Kernel/Migrate/d7/MigrateCustomBlockTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Migrate/d7/MigrateCustomBlockTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateCustomBlockTest extends MigrateDrupal7TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'block_content',
     'filter',
     'text',
diff --git a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTest.php b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTest.php
index 22ab03c1f9..7f84eb5820 100644
--- a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTest.php
@@ -15,7 +15,7 @@ class BoxTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content', 'migrate_drupal'];
+  protected static $modules = ['block_content', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTranslationTest.php b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTranslationTest.php
index 3c3b89e30d..6bf50176fd 100644
--- a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTranslationTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d6/BoxTranslationTest.php
@@ -16,7 +16,7 @@ class BoxTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content', 'migrate_drupal'];
+  protected static $modules = ['block_content', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d7/BlockCustomTest.php b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d7/BlockCustomTest.php
index 55419e3878..3a2e02d534 100644
--- a/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d7/BlockCustomTest.php
+++ b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d7/BlockCustomTest.php
@@ -15,7 +15,7 @@ class BlockCustomTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content', 'migrate_drupal'];
+  protected static $modules = ['block_content', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/block_place/tests/src/Functional/BlockPlaceTest.php b/core/modules/block_place/tests/src/Functional/BlockPlaceTest.php
index 8e89048acd..919be0c25d 100644
--- a/core/modules/block_place/tests/src/Functional/BlockPlaceTest.php
+++ b/core/modules/block_place/tests/src/Functional/BlockPlaceTest.php
@@ -17,7 +17,7 @@ class BlockPlaceTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_place', 'toolbar'];
+  protected static $modules = ['block', 'block_place', 'toolbar'];
 
   /**
    * Tests placing blocks as an admin.
diff --git a/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php b/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
index a863ff1529..40ed9da5ca 100644
--- a/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
+++ b/core/modules/book/tests/src/Functional/BookBreadcrumbTest.php
@@ -16,7 +16,7 @@ class BookBreadcrumbTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['book', 'block', 'book_breadcrumb_test'];
+  protected static $modules = ['book', 'block', 'book_breadcrumb_test'];
 
   /**
    * A book node.
diff --git a/core/modules/book/tests/src/Functional/BookContentModerationTest.php b/core/modules/book/tests/src/Functional/BookContentModerationTest.php
index b9c7cd2841..2cdd45d891 100644
--- a/core/modules/book/tests/src/Functional/BookContentModerationTest.php
+++ b/core/modules/book/tests/src/Functional/BookContentModerationTest.php
@@ -20,7 +20,7 @@ class BookContentModerationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['book', 'block', 'book_test', 'content_moderation'];
+  protected static $modules = ['book', 'block', 'book_test', 'content_moderation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Functional/BookInstallTest.php b/core/modules/book/tests/src/Functional/BookInstallTest.php
index b5658bdc72..be0ee9a83b 100644
--- a/core/modules/book/tests/src/Functional/BookInstallTest.php
+++ b/core/modules/book/tests/src/Functional/BookInstallTest.php
@@ -17,7 +17,7 @@ class BookInstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Functional/BookTest.php b/core/modules/book/tests/src/Functional/BookTest.php
index d02dfd50d9..0097c1f789 100644
--- a/core/modules/book/tests/src/Functional/BookTest.php
+++ b/core/modules/book/tests/src/Functional/BookTest.php
@@ -20,7 +20,7 @@ class BookTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['book', 'block', 'node_access_test', 'book_test'];
+  protected static $modules = ['book', 'block', 'node_access_test', 'book_test'];
 
   /**
    * A user with permission to view a book and access printer-friendly version.
diff --git a/core/modules/book/tests/src/Functional/Views/BookRelationshipTest.php b/core/modules/book/tests/src/Functional/Views/BookRelationshipTest.php
index 9ee79c78dc..41d626fd40 100644
--- a/core/modules/book/tests/src/Functional/Views/BookRelationshipTest.php
+++ b/core/modules/book/tests/src/Functional/Views/BookRelationshipTest.php
@@ -26,7 +26,7 @@ class BookRelationshipTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['book_test_views', 'book', 'views'];
+  protected static $modules = ['book_test_views', 'book', 'views'];
 
   /**
    * A book node.
diff --git a/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php b/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
index dc9b8125cc..a4247167cf 100644
--- a/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
+++ b/core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
@@ -17,7 +17,7 @@ class BookJavascriptTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book'];
+  protected static $modules = ['book'];
 
   /**
    * Tests re-ordering of books.
diff --git a/core/modules/book/tests/src/Kernel/BookPendingRevisionTest.php b/core/modules/book/tests/src/Kernel/BookPendingRevisionTest.php
index ababb3daaa..516b1e1653 100644
--- a/core/modules/book/tests/src/Kernel/BookPendingRevisionTest.php
+++ b/core/modules/book/tests/src/Kernel/BookPendingRevisionTest.php
@@ -18,7 +18,7 @@ class BookPendingRevisionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'filter', 'text', 'node', 'book'];
+  protected static $modules = ['system', 'user', 'field', 'filter', 'text', 'node', 'book'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Kernel/BookUninstallTest.php b/core/modules/book/tests/src/Kernel/BookUninstallTest.php
index d4205ebf11..a330ae4c83 100644
--- a/core/modules/book/tests/src/Kernel/BookUninstallTest.php
+++ b/core/modules/book/tests/src/Kernel/BookUninstallTest.php
@@ -18,7 +18,7 @@ class BookUninstallTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'filter', 'text', 'node', 'book'];
+  protected static $modules = ['system', 'user', 'field', 'filter', 'text', 'node', 'book'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookConfigsTest.php b/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookConfigsTest.php
index 7498638455..98f3e74f78 100644
--- a/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookConfigsTest.php
+++ b/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateBookConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book'];
+  protected static $modules = ['book'];
 
   /**
    * Data provider for testBookSettings().
diff --git a/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookTest.php b/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookTest.php
index cab65e39c2..28168f8574 100644
--- a/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookTest.php
+++ b/core/modules/book/tests/src/Kernel/Migrate/d6/MigrateBookTest.php
@@ -15,7 +15,7 @@ class MigrateBookTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book', 'menu_ui'];
+  protected static $modules = ['book', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookConfigsTest.php b/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookConfigsTest.php
index a5504c9104..a3be4b8451 100644
--- a/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookConfigsTest.php
+++ b/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateBookConfigsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book', 'node'];
+  protected static $modules = ['book', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookTest.php b/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookTest.php
index 1d0e25365a..3e3855fb15 100644
--- a/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookTest.php
+++ b/core/modules/book/tests/src/Kernel/Migrate/d7/MigrateBookTest.php
@@ -15,7 +15,7 @@ class MigrateBookTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'book',
     'menu_ui',
     'node',
diff --git a/core/modules/book/tests/src/Kernel/Plugin/migrate/source/BookTest.php b/core/modules/book/tests/src/Kernel/Plugin/migrate/source/BookTest.php
index 0259474259..f31eb0c933 100644
--- a/core/modules/book/tests/src/Kernel/Plugin/migrate/source/BookTest.php
+++ b/core/modules/book/tests/src/Kernel/Plugin/migrate/source/BookTest.php
@@ -15,7 +15,7 @@ class BookTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book', 'migrate_drupal', 'node'];
+  protected static $modules = ['book', 'migrate_drupal', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php b/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php
index dc8175787b..725d858ef5 100644
--- a/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php
+++ b/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php
@@ -16,7 +16,7 @@ class BreakpointDiscoveryTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'breakpoint', 'breakpoint_module_test'];
+  protected static $modules = ['system', 'breakpoint', 'breakpoint_module_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php b/core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php
index aeba60fd75..6d290414c4 100644
--- a/core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php
+++ b/core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php
@@ -20,7 +20,7 @@ class CKEditorAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'ckeditor'];
+  protected static $modules = ['filter', 'editor', 'ckeditor'];
 
   /**
    * A user with the 'administer filters' permission.
diff --git a/core/modules/ckeditor/tests/src/Functional/CKEditorLoadingTest.php b/core/modules/ckeditor/tests/src/Functional/CKEditorLoadingTest.php
index cad0947dcf..213a417e12 100644
--- a/core/modules/ckeditor/tests/src/Functional/CKEditorLoadingTest.php
+++ b/core/modules/ckeditor/tests/src/Functional/CKEditorLoadingTest.php
@@ -18,7 +18,7 @@ class CKEditorLoadingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'ckeditor', 'node'];
+  protected static $modules = ['filter', 'editor', 'ckeditor', 'node'];
 
   /**
    * An untrusted user with access to only the 'plain_text' format.
diff --git a/core/modules/ckeditor/tests/src/Functional/CKEditorStylesComboAdminTest.php b/core/modules/ckeditor/tests/src/Functional/CKEditorStylesComboAdminTest.php
index 9f41834de5..75e62feaca 100644
--- a/core/modules/ckeditor/tests/src/Functional/CKEditorStylesComboAdminTest.php
+++ b/core/modules/ckeditor/tests/src/Functional/CKEditorStylesComboAdminTest.php
@@ -18,7 +18,7 @@ class CKEditorStylesComboAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'ckeditor'];
+  protected static $modules = ['filter', 'editor', 'ckeditor'];
 
   /**
    * A user with the 'administer filters' permission.
diff --git a/core/modules/ckeditor/tests/src/Functional/CKEditorToolbarButtonTest.php b/core/modules/ckeditor/tests/src/Functional/CKEditorToolbarButtonTest.php
index c47b67b0b4..631b10edc5 100644
--- a/core/modules/ckeditor/tests/src/Functional/CKEditorToolbarButtonTest.php
+++ b/core/modules/ckeditor/tests/src/Functional/CKEditorToolbarButtonTest.php
@@ -19,7 +19,7 @@ class CKEditorToolbarButtonTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'ckeditor', 'locale'];
+  protected static $modules = ['filter', 'editor', 'ckeditor', 'locale'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/ckeditor/tests/src/FunctionalJavascript/AjaxCssTest.php b/core/modules/ckeditor/tests/src/FunctionalJavascript/AjaxCssTest.php
index ddb53d8303..d42b9dbf77 100644
--- a/core/modules/ckeditor/tests/src/FunctionalJavascript/AjaxCssTest.php
+++ b/core/modules/ckeditor/tests/src/FunctionalJavascript/AjaxCssTest.php
@@ -16,7 +16,7 @@ class AjaxCssTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ckeditor', 'ckeditor_test'];
+  protected static $modules = ['ckeditor', 'ckeditor_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
index a9ee69719b..25418332ad 100644
--- a/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
+++ b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
@@ -27,7 +27,7 @@ class CKEditorIntegrationTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'ckeditor', 'filter'];
+  protected static $modules = ['node', 'ckeditor', 'filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/ckeditor/tests/src/Kernel/CKEditorPluginManagerTest.php b/core/modules/ckeditor/tests/src/Kernel/CKEditorPluginManagerTest.php
index 5664728ec3..16be3b0c0c 100644
--- a/core/modules/ckeditor/tests/src/Kernel/CKEditorPluginManagerTest.php
+++ b/core/modules/ckeditor/tests/src/Kernel/CKEditorPluginManagerTest.php
@@ -18,7 +18,7 @@ class CKEditorPluginManagerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'filter', 'editor', 'ckeditor'];
+  protected static $modules = ['system', 'user', 'filter', 'editor', 'ckeditor'];
 
   /**
    * The manager for "CKEditor plugin" plugins.
diff --git a/core/modules/ckeditor/tests/src/Kernel/CKEditorTest.php b/core/modules/ckeditor/tests/src/Kernel/CKEditorTest.php
index 6ff5d20e6a..d93a4dc1fa 100644
--- a/core/modules/ckeditor/tests/src/Kernel/CKEditorTest.php
+++ b/core/modules/ckeditor/tests/src/Kernel/CKEditorTest.php
@@ -19,7 +19,7 @@ class CKEditorTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'filter', 'editor', 'ckeditor', 'filter_test'];
+  protected static $modules = ['system', 'user', 'filter', 'editor', 'ckeditor', 'filter_test'];
 
   /**
    * An instance of the "CKEditor" text editor plugin.
diff --git a/core/modules/ckeditor/tests/src/Kernel/Plugin/CKEditorPlugin/InternalTest.php b/core/modules/ckeditor/tests/src/Kernel/Plugin/CKEditorPlugin/InternalTest.php
index aecc228020..afd916bb57 100644
--- a/core/modules/ckeditor/tests/src/Kernel/Plugin/CKEditorPlugin/InternalTest.php
+++ b/core/modules/ckeditor/tests/src/Kernel/Plugin/CKEditorPlugin/InternalTest.php
@@ -18,7 +18,7 @@ class InternalTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'ckeditor',
     'ckeditor_test',
     'filter',
diff --git a/core/modules/color/tests/src/Functional/ColorConfigSchemaTest.php b/core/modules/color/tests/src/Functional/ColorConfigSchemaTest.php
index f93f3587b1..8793151b49 100644
--- a/core/modules/color/tests/src/Functional/ColorConfigSchemaTest.php
+++ b/core/modules/color/tests/src/Functional/ColorConfigSchemaTest.php
@@ -16,7 +16,7 @@ class ColorConfigSchemaTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['color'];
+  protected static $modules = ['color'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/color/tests/src/Functional/ColorSafePreviewTest.php b/core/modules/color/tests/src/Functional/ColorSafePreviewTest.php
index 9f6914c996..c13a403b26 100644
--- a/core/modules/color/tests/src/Functional/ColorSafePreviewTest.php
+++ b/core/modules/color/tests/src/Functional/ColorSafePreviewTest.php
@@ -17,7 +17,7 @@ class ColorSafePreviewTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['color', 'color_test'];
+  protected static $modules = ['color', 'color_test'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/color/tests/src/Functional/ColorTest.php b/core/modules/color/tests/src/Functional/ColorTest.php
index de3ab69160..80d0851ce2 100644
--- a/core/modules/color/tests/src/Functional/ColorTest.php
+++ b/core/modules/color/tests/src/Functional/ColorTest.php
@@ -17,7 +17,7 @@ class ColorTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['color', 'color_test', 'block', 'file'];
+  protected static $modules = ['color', 'color_test', 'block', 'file'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/color/tests/src/Kernel/Migrate/d7/MigrateColorTest.php b/core/modules/color/tests/src/Kernel/Migrate/d7/MigrateColorTest.php
index 946d1e38c5..598fba6651 100644
--- a/core/modules/color/tests/src/Kernel/Migrate/d7/MigrateColorTest.php
+++ b/core/modules/color/tests/src/Kernel/Migrate/d7/MigrateColorTest.php
@@ -14,7 +14,7 @@ class MigrateColorTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['color'];
+  protected static $modules = ['color'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/color/tests/src/Kernel/Plugin/migrate/source/d7/ColorTest.php b/core/modules/color/tests/src/Kernel/Plugin/migrate/source/d7/ColorTest.php
index cb634a9c63..a2ed9b80ba 100644
--- a/core/modules/color/tests/src/Kernel/Plugin/migrate/source/d7/ColorTest.php
+++ b/core/modules/color/tests/src/Kernel/Plugin/migrate/source/d7/ColorTest.php
@@ -16,7 +16,7 @@ class ColorTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['color', 'migrate_drupal'];
+  protected static $modules = ['color', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/src/Tests/CommentTestBase.php b/core/modules/comment/src/Tests/CommentTestBase.php
index 3b923ffaf4..efe90e503c 100644
--- a/core/modules/comment/src/Tests/CommentTestBase.php
+++ b/core/modules/comment/src/Tests/CommentTestBase.php
@@ -29,7 +29,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime'];
+  protected static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime'];
 
   /**
    * An administrative user with permission to configure comment settings.
diff --git a/core/modules/comment/src/Tests/Views/CommentTestBase.php b/core/modules/comment/src/Tests/Views/CommentTestBase.php
index c364e2631f..e0f5178ba3 100644
--- a/core/modules/comment/src/Tests/Views/CommentTestBase.php
+++ b/core/modules/comment/src/Tests/Views/CommentTestBase.php
@@ -26,7 +26,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'comment_test_views'];
+  protected static $modules = ['node', 'comment', 'comment_test_views'];
 
   /**
    * A normal user with permission to post comments (without approval).
diff --git a/core/modules/comment/tests/src/Functional/CommentAccessTest.php b/core/modules/comment/tests/src/Functional/CommentAccessTest.php
index b2e4725785..92ff311865 100644
--- a/core/modules/comment/tests/src/Functional/CommentAccessTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentAccessTest.php
@@ -19,7 +19,7 @@ class CommentAccessTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'comment',
   ];
diff --git a/core/modules/comment/tests/src/Functional/CommentActionsTest.php b/core/modules/comment/tests/src/Functional/CommentActionsTest.php
index 326749b7c0..76f5e25530 100644
--- a/core/modules/comment/tests/src/Functional/CommentActionsTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentActionsTest.php
@@ -17,7 +17,7 @@ class CommentActionsTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['dblog', 'action'];
+  protected static $modules = ['dblog', 'action'];
 
   /**
    * Tests comment publish and unpublish actions.
diff --git a/core/modules/comment/tests/src/Functional/CommentBlockTest.php b/core/modules/comment/tests/src/Functional/CommentBlockTest.php
index 0e2ee1f05f..b87b548290 100644
--- a/core/modules/comment/tests/src/Functional/CommentBlockTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentBlockTest.php
@@ -17,7 +17,7 @@ class CommentBlockTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'views'];
+  protected static $modules = ['block', 'views'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Functional/CommentBookTest.php b/core/modules/comment/tests/src/Functional/CommentBookTest.php
index 45693b57fb..118357b131 100644
--- a/core/modules/comment/tests/src/Functional/CommentBookTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentBookTest.php
@@ -22,7 +22,7 @@ class CommentBookTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['book', 'comment'];
+  protected static $modules = ['book', 'comment'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Functional/CommentCacheTagsTest.php b/core/modules/comment/tests/src/Functional/CommentCacheTagsTest.php
index 0b0f4863af..86b7a32bb3 100644
--- a/core/modules/comment/tests/src/Functional/CommentCacheTagsTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentCacheTagsTest.php
@@ -25,7 +25,7 @@ class CommentCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment'];
+  protected static $modules = ['comment'];
 
   /**
    * @var \Drupal\entity_test\Entity\EntityTest
diff --git a/core/modules/comment/tests/src/Functional/CommentEntityTest.php b/core/modules/comment/tests/src/Functional/CommentEntityTest.php
index 62d57f0371..39e87f30d7 100644
--- a/core/modules/comment/tests/src/Functional/CommentEntityTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentEntityTest.php
@@ -21,7 +21,7 @@ class CommentEntityTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime', 'taxonomy'];
+  protected static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime', 'taxonomy'];
 
   use TaxonomyTestTrait;
 
diff --git a/core/modules/comment/tests/src/Functional/CommentFieldsTest.php b/core/modules/comment/tests/src/Functional/CommentFieldsTest.php
index 2df9973348..b2485f88ba 100644
--- a/core/modules/comment/tests/src/Functional/CommentFieldsTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentFieldsTest.php
@@ -19,7 +19,7 @@ class CommentFieldsTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui'];
+  protected static $modules = ['field_ui'];
 
   /**
    * Tests that the default 'comment_body' field is correctly added.
diff --git a/core/modules/comment/tests/src/Functional/CommentLanguageTest.php b/core/modules/comment/tests/src/Functional/CommentLanguageTest.php
index ce9a9abb04..2eb750b847 100644
--- a/core/modules/comment/tests/src/Functional/CommentLanguageTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentLanguageTest.php
@@ -26,7 +26,7 @@ class CommentLanguageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'language', 'language_test', 'comment_test'];
+  protected static $modules = ['node', 'language', 'language_test', 'comment_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Functional/CommentLinksAlterTest.php b/core/modules/comment/tests/src/Functional/CommentLinksAlterTest.php
index e49361b651..259dd48a9c 100644
--- a/core/modules/comment/tests/src/Functional/CommentLinksAlterTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentLinksAlterTest.php
@@ -9,7 +9,7 @@
  */
 class CommentLinksAlterTest extends CommentTestBase {
 
-  public static $modules = ['comment_test'];
+  protected static $modules = ['comment_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Functional/CommentLinksTest.php b/core/modules/comment/tests/src/Functional/CommentLinksTest.php
index 3d79d96642..b9f233cb87 100644
--- a/core/modules/comment/tests/src/Functional/CommentLinksTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentLinksTest.php
@@ -36,7 +36,7 @@ class CommentLinksTest extends CommentTestBase {
    *
    * @todo Remove this dependency.
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * Tests that comment links are output and can be hidden.
diff --git a/core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php b/core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php
index 69f7bdeeed..4e4baab384 100644
--- a/core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php
@@ -22,7 +22,7 @@ class CommentNewIndicatorTest extends CommentTestBase {
    *
    * @todo Remove this dependency.
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * Get node "x new comments" metadata from the server for the current user.
diff --git a/core/modules/comment/tests/src/Functional/CommentNodeAccessTest.php b/core/modules/comment/tests/src/Functional/CommentNodeAccessTest.php
index 6842dc137f..3decbf8868 100644
--- a/core/modules/comment/tests/src/Functional/CommentNodeAccessTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentNodeAccessTest.php
@@ -19,7 +19,7 @@ class CommentNodeAccessTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test'];
+  protected static $modules = ['node_access_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Functional/CommentNonNodeTest.php b/core/modules/comment/tests/src/Functional/CommentNonNodeTest.php
index d404747844..7b41033f89 100644
--- a/core/modules/comment/tests/src/Functional/CommentNonNodeTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentNonNodeTest.php
@@ -25,7 +25,7 @@ class CommentNonNodeTest extends BrowserTestBase {
   use FieldUiTestTrait;
   use CommentTestTrait;
 
-  public static $modules = ['comment', 'user', 'field_ui', 'entity_test', 'block'];
+  protected static $modules = ['comment', 'user', 'field_ui', 'entity_test', 'block'];
 
   /**
    * An administrative user with permission to configure comment settings.
diff --git a/core/modules/comment/tests/src/Functional/CommentRssTest.php b/core/modules/comment/tests/src/Functional/CommentRssTest.php
index 60708bd4a8..2a56056a2f 100644
--- a/core/modules/comment/tests/src/Functional/CommentRssTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentRssTest.php
@@ -21,7 +21,7 @@ class CommentRssTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/CommentStatusFieldAccessTest.php b/core/modules/comment/tests/src/Functional/CommentStatusFieldAccessTest.php
index d2495d3791..094f1e6003 100644
--- a/core/modules/comment/tests/src/Functional/CommentStatusFieldAccessTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentStatusFieldAccessTest.php
@@ -37,7 +37,7 @@ class CommentStatusFieldAccessTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'comment',
     'user',
diff --git a/core/modules/comment/tests/src/Functional/CommentTestBase.php b/core/modules/comment/tests/src/Functional/CommentTestBase.php
index 7cadcbffe9..bd7721215a 100644
--- a/core/modules/comment/tests/src/Functional/CommentTestBase.php
+++ b/core/modules/comment/tests/src/Functional/CommentTestBase.php
@@ -23,7 +23,7 @@
    *
    * @var array
    */
-  public static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime'];
+  protected static $modules = ['block', 'comment', 'node', 'history', 'field_ui', 'datetime'];
 
   /**
    * An administrative user with permission to configure comment settings.
diff --git a/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php b/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
index 47c980418a..6aece45aed 100644
--- a/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentTokenReplaceTest.php
@@ -24,7 +24,7 @@ class CommentTokenReplaceTest extends CommentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Creates a comment, then tests the tokens generated from it.
diff --git a/core/modules/comment/tests/src/Functional/CommentTranslationUITest.php b/core/modules/comment/tests/src/Functional/CommentTranslationUITest.php
index f6bec9c7d3..3e8990fb83 100644
--- a/core/modules/comment/tests/src/Functional/CommentTranslationUITest.php
+++ b/core/modules/comment/tests/src/Functional/CommentTranslationUITest.php
@@ -47,7 +47,7 @@ class CommentTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'node', 'comment'];
+  protected static $modules = ['language', 'content_translation', 'node', 'comment'];
 
   protected function setUp() {
     $this->entityTypeId = 'comment';
diff --git a/core/modules/comment/tests/src/Functional/CommentUninstallTest.php b/core/modules/comment/tests/src/Functional/CommentUninstallTest.php
index 96d7eeae8d..03f904f830 100644
--- a/core/modules/comment/tests/src/Functional/CommentUninstallTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentUninstallTest.php
@@ -21,7 +21,7 @@ class CommentUninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'node'];
+  protected static $modules = ['comment', 'node'];
 
   protected function setUp() {
     parent::setup();
diff --git a/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonBasicAuthTest.php
index 7d766fdfca..a15540d96d 100644
--- a/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class CommentHalJsonBasicAuthTest extends CommentHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonTestBase.php b/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonTestBase.php
index a9cf1c2425..49c77166f7 100644
--- a/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonTestBase.php
+++ b/core/modules/comment/tests/src/Functional/Hal/CommentHalJsonTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonAnonTest.php b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonAnonTest.php
index 179ae18612..7b0ddb77e0 100644
--- a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonAnonTest.php
+++ b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class CommentTypeHalJsonAnonTest extends CommentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonBasicAuthTest.php
index 3a014bd1d1..02f6a46a32 100644
--- a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class CommentTypeHalJsonBasicAuthTest extends CommentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonCookieTest.php b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonCookieTest.php
index 9d6440ead4..56b0451ad7 100644
--- a/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonCookieTest.php
+++ b/core/modules/comment/tests/src/Functional/Hal/CommentTypeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class CommentTypeHalJsonCookieTest extends CommentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentJsonBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Rest/CommentJsonBasicAuthTest.php
index a4f72551a4..28201fcc1e 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentJsonBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class CommentJsonBasicAuthTest extends CommentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentResourceTestBase.php b/core/modules/comment/tests/src/Functional/Rest/CommentResourceTestBase.php
index 7d1abdbb68..bc0023a0d2 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentResourceTestBase.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentResourceTestBase.php
@@ -19,7 +19,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'entity_test'];
+  protected static $modules = ['comment', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentTypeJsonBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Rest/CommentTypeJsonBasicAuthTest.php
index c947dbc92c..6df7cc0a52 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentTypeJsonBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentTypeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class CommentTypeJsonBasicAuthTest extends CommentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentTypeResourceTestBase.php b/core/modules/comment/tests/src/Functional/Rest/CommentTypeResourceTestBase.php
index 5d9b413362..eb4574f9a0 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentTypeResourceTestBase.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentTypeResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentTypeXmlBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Rest/CommentTypeXmlBasicAuthTest.php
index e92f2bcc65..f0f7fdff97 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentTypeXmlBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentTypeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class CommentTypeXmlBasicAuthTest extends CommentTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Rest/CommentXmlBasicAuthTest.php b/core/modules/comment/tests/src/Functional/Rest/CommentXmlBasicAuthTest.php
index d1f38e44a4..3c2f296093 100644
--- a/core/modules/comment/tests/src/Functional/Rest/CommentXmlBasicAuthTest.php
+++ b/core/modules/comment/tests/src/Functional/Rest/CommentXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class CommentXmlBasicAuthTest extends CommentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Functional/Views/CommentFieldFilterTest.php b/core/modules/comment/tests/src/Functional/Views/CommentFieldFilterTest.php
index dabacc3bed..ec43ab73d9 100644
--- a/core/modules/comment/tests/src/Functional/Views/CommentFieldFilterTest.php
+++ b/core/modules/comment/tests/src/Functional/Views/CommentFieldFilterTest.php
@@ -15,7 +15,7 @@ class CommentFieldFilterTest extends CommentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/comment/tests/src/Functional/Views/CommentRestExportTest.php b/core/modules/comment/tests/src/Functional/Views/CommentRestExportTest.php
index c6e39f8316..acfbe0288d 100644
--- a/core/modules/comment/tests/src/Functional/Views/CommentRestExportTest.php
+++ b/core/modules/comment/tests/src/Functional/Views/CommentRestExportTest.php
@@ -22,7 +22,7 @@ class CommentRestExportTest extends CommentTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'comment_test_views', 'rest', 'hal'];
+  protected static $modules = ['node', 'comment', 'comment_test_views', 'rest', 'hal'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/comment/tests/src/Functional/Views/CommentTestBase.php b/core/modules/comment/tests/src/Functional/Views/CommentTestBase.php
index a9444a2320..b3995af098 100644
--- a/core/modules/comment/tests/src/Functional/Views/CommentTestBase.php
+++ b/core/modules/comment/tests/src/Functional/Views/CommentTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'comment_test_views'];
+  protected static $modules = ['node', 'comment', 'comment_test_views'];
 
   /**
    * A normal user with permission to post comments (without approval).
diff --git a/core/modules/comment/tests/src/Functional/Views/DefaultViewRecentCommentsTest.php b/core/modules/comment/tests/src/Functional/Views/DefaultViewRecentCommentsTest.php
index 4085f4f47b..80b59e8a30 100644
--- a/core/modules/comment/tests/src/Functional/Views/DefaultViewRecentCommentsTest.php
+++ b/core/modules/comment/tests/src/Functional/Views/DefaultViewRecentCommentsTest.php
@@ -22,7 +22,7 @@ class DefaultViewRecentCommentsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'block'];
+  protected static $modules = ['node', 'comment', 'block'];
 
   /**
    * Number of results for the Master display.
diff --git a/core/modules/comment/tests/src/Functional/Views/NodeCommentsTest.php b/core/modules/comment/tests/src/Functional/Views/NodeCommentsTest.php
index e2c5d15ef5..ae8981a446 100644
--- a/core/modules/comment/tests/src/Functional/Views/NodeCommentsTest.php
+++ b/core/modules/comment/tests/src/Functional/Views/NodeCommentsTest.php
@@ -14,7 +14,7 @@ class NodeCommentsTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['history'];
+  protected static $modules = ['history'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/comment/tests/src/Functional/Views/WizardTest.php b/core/modules/comment/tests/src/Functional/Views/WizardTest.php
index 9c02fccdac..d21c14e90c 100644
--- a/core/modules/comment/tests/src/Functional/Views/WizardTest.php
+++ b/core/modules/comment/tests/src/Functional/Views/WizardTest.php
@@ -21,7 +21,7 @@ class WizardTest extends WizardTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php b/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php
index d907233409..b46e12f331 100644
--- a/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php
@@ -15,7 +15,7 @@ class CommentBundlesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'node', 'taxonomy', 'user'];
+  protected static $modules = ['comment', 'node', 'taxonomy', 'user'];
 
   /**
    * Entity type ids to use for target_entity_type_id on comment bundles.
diff --git a/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php b/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
index bdea71df15..6ec7323f5d 100644
--- a/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentDefaultFormatterCacheTagsTest.php
@@ -26,7 +26,7 @@ class CommentDefaultFormatterCacheTagsTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'comment'];
+  protected static $modules = ['entity_test', 'comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/CommentFieldAccessTest.php b/core/modules/comment/tests/src/Kernel/CommentFieldAccessTest.php
index c17f247dff..de8bfc2a9b 100644
--- a/core/modules/comment/tests/src/Kernel/CommentFieldAccessTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentFieldAccessTest.php
@@ -30,7 +30,7 @@ class CommentFieldAccessTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'entity_test', 'user'];
+  protected static $modules = ['comment', 'entity_test', 'user'];
 
   /**
    * Fields that only users with administer comments permissions can change.
diff --git a/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php b/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php
index 88311994c4..25f89d41c0 100644
--- a/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php
@@ -20,7 +20,7 @@ class CommentIntegrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'field', 'entity_test', 'user', 'system', 'dblog'];
+  protected static $modules = ['comment', 'field', 'entity_test', 'user', 'system', 'dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/CommentItemTest.php b/core/modules/comment/tests/src/Kernel/CommentItemTest.php
index 85f6112561..51e7315de9 100644
--- a/core/modules/comment/tests/src/Kernel/CommentItemTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentItemTest.php
@@ -23,7 +23,7 @@ class CommentItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'entity_test', 'user'];
+  protected static $modules = ['comment', 'entity_test', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/comment/tests/src/Kernel/CommentStringIdEntitiesTest.php b/core/modules/comment/tests/src/Kernel/CommentStringIdEntitiesTest.php
index adbe1b08d5..6a8a93cc20 100644
--- a/core/modules/comment/tests/src/Kernel/CommentStringIdEntitiesTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentStringIdEntitiesTest.php
@@ -18,7 +18,7 @@ class CommentStringIdEntitiesTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'user',
     'field',
diff --git a/core/modules/comment/tests/src/Kernel/CommentValidationTest.php b/core/modules/comment/tests/src/Kernel/CommentValidationTest.php
index 1d81d55ece..0510ee8abb 100644
--- a/core/modules/comment/tests/src/Kernel/CommentValidationTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentValidationTest.php
@@ -19,7 +19,7 @@ class CommentValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'node'];
+  protected static $modules = ['comment', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php b/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php
index 3b0674222c..b4ee03dcdc 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php
@@ -19,7 +19,7 @@ class MigrateCommentStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'node'];
+  protected static $modules = ['comment', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityDisplayTest.php
index 2c13371fb8..2341aea0bd 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityDisplayTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityDisplayTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'menu_ui'];
+  protected static $modules = ['comment', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplaySubjectTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplaySubjectTest.php
index 74a871521a..be7d16c3e3 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplaySubjectTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplaySubjectTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityFormDisplaySubjectTest extends MigrateDrupal6TestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment'];
+  protected static $modules = ['comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplayTest.php
index c9e0d6b8a6..cc4b384d4c 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplayTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentEntityFormDisplayTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityFormDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'menu_ui'];
+  protected static $modules = ['comment', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldInstanceTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldInstanceTest.php
index 03469c4808..f0a65928ee 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldInstanceTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldInstanceTest.php
@@ -16,7 +16,7 @@ class MigrateCommentFieldInstanceTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'menu_ui'];
+  protected static $modules = ['comment', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldTest.php
index e08e2d2e20..7974cc069b 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentFieldTest.php
@@ -16,7 +16,7 @@ class MigrateCommentFieldTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'menu_ui'];
+  protected static $modules = ['comment', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
index 06ca65582e..21c0f75bff 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
@@ -20,7 +20,7 @@ class MigrateCommentTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'menu_ui'];
+  protected static $modules = ['comment', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTypeTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTypeTest.php
index 2fa60826de..339d8f804b 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTypeTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTypeTest.php
@@ -16,7 +16,7 @@ class MigrateCommentTypeTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment'];
+  protected static $modules = ['comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityDisplayTest.php
index aeb1e923ac..42cac7d899 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityDisplayTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityDisplayTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityDisplayTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'comment', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplaySubjectTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplaySubjectTest.php
index 2c3025a449..372dbcfd76 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplaySubjectTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplaySubjectTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityFormDisplaySubjectTest extends MigrateDrupal7TestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'comment', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplayTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplayTest.php
index 2f0f6f318c..271525127f 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplayTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentEntityFormDisplayTest.php
@@ -16,7 +16,7 @@ class MigrateCommentEntityFormDisplayTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'comment', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldInstanceTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldInstanceTest.php
index 4b928f7a3d..4f49ac4c47 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldInstanceTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldInstanceTest.php
@@ -16,7 +16,7 @@ class MigrateCommentFieldInstanceTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'comment', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldTest.php
index aa59f678f7..5d4e19b6f7 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentFieldTest.php
@@ -16,7 +16,7 @@ class MigrateCommentFieldTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text'];
+  protected static $modules = ['node', 'comment', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTest.php
index 68df72f376..0341e150fa 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTest.php
@@ -17,7 +17,7 @@ class MigrateCommentTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'filter',
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTypeTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTypeTest.php
index b0c96dab83..2eb5b41597 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTypeTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d7/MigrateCommentTypeTest.php
@@ -16,7 +16,7 @@ class MigrateCommentTypeTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment', 'text'];
+  protected static $modules = ['node', 'comment', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentSourceWithHighWaterTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentSourceWithHighWaterTest.php
index a4d91c4686..38099d1cf8 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentSourceWithHighWaterTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentSourceWithHighWaterTest.php
@@ -16,7 +16,7 @@ class CommentSourceWithHighWaterTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentTest.php
index 0372f0f9ac..e32b9d3838 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentTest.php
@@ -15,7 +15,7 @@ class CommentTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariablePerCommentTypeTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariablePerCommentTypeTest.php
index dd1b1fd06c..895ed97ebd 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariablePerCommentTypeTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariablePerCommentTypeTest.php
@@ -15,7 +15,7 @@ class CommentVariablePerCommentTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariableTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariableTest.php
index a84c776b77..74cc6b743d 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariableTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d6/CommentVariableTest.php
@@ -15,7 +15,7 @@ class CommentVariableTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTest.php
index dc99489563..b40e974d7c 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTest.php
@@ -15,7 +15,7 @@ class CommentTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTypeTest.php b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTypeTest.php
index 11f3db5842..6355c16005 100644
--- a/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTypeTest.php
+++ b/core/modules/comment/tests/src/Kernel/Plugin/migrate/source/d7/CommentTypeTest.php
@@ -15,7 +15,7 @@ class CommentTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'migrate_drupal'];
+  protected static $modules = ['comment', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Views/CommentAdminViewTest.php b/core/modules/comment/tests/src/Kernel/Views/CommentAdminViewTest.php
index 86e8949905..fc8d21cc63 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentAdminViewTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentAdminViewTest.php
@@ -34,7 +34,7 @@ class CommentAdminViewTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'user',
     'comment',
     'entity_test',
diff --git a/core/modules/comment/tests/src/Kernel/Views/CommentLinksTest.php b/core/modules/comment/tests/src/Kernel/Views/CommentLinksTest.php
index acd2cf6e72..4546ab27b4 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentLinksTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentLinksTest.php
@@ -22,7 +22,7 @@ class CommentLinksTest extends CommentViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php b/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
index 2144ebd94a..2e6bcb686b 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
@@ -27,7 +27,7 @@ class CommentUserNameTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'comment', 'entity_test'];
+  protected static $modules = ['user', 'comment', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php b/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php
index 1ca5e43971..89c93c6458 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php
@@ -17,7 +17,7 @@ class CommentViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'entity_test'];
+  protected static $modules = ['comment', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/comment/tests/src/Kernel/Views/CommentViewsKernelTestBase.php b/core/modules/comment/tests/src/Kernel/Views/CommentViewsKernelTestBase.php
index 516750382c..e112b8a129 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentViewsKernelTestBase.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentViewsKernelTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['comment_test_views', 'user', 'comment'];
+  protected static $modules = ['comment_test_views', 'user', 'comment'];
 
   /**
    * Admin user.
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonAnonTest.php b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonAnonTest.php
index d874f45f26..19285aa020 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonAnonTest.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ConfigTestHalJsonAnonTest extends ConfigTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonBasicAuthTest.php b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonBasicAuthTest.php
index 01a69c329d..7fdb96b307 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonBasicAuthTest.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ConfigTestHalJsonBasicAuthTest extends ConfigTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonCookieTest.php b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonCookieTest.php
index eb670d2a4e..dedbac9131 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonCookieTest.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Hal/ConfigTestHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ConfigTestHalJsonCookieTest extends ConfigTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestJsonBasicAuthTest.php b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestJsonBasicAuthTest.php
index 87c415840a..ac9fbe918d 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestJsonBasicAuthTest.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ConfigTestJsonBasicAuthTest extends ConfigTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestResourceTestBase.php b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestResourceTestBase.php
index 9ab65d76ae..ba4dd122df 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestResourceTestBase.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test', 'config_test_rest'];
+  protected static $modules = ['config_test', 'config_test_rest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestXmlBasicAuthTest.php b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestXmlBasicAuthTest.php
index c65028f212..c7c21adea0 100644
--- a/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestXmlBasicAuthTest.php
+++ b/core/modules/config/tests/config_test/tests/src/Functional/Rest/ConfigTestXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ConfigTestXmlBasicAuthTest extends ConfigTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php b/core/modules/config/tests/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php
index f2f8730a02..f263255bd7 100644
--- a/core/modules/config/tests/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php
+++ b/core/modules/config/tests/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php
@@ -17,7 +17,7 @@ class CacheabilityMetadataConfigOverrideIntegrationTest extends BrowserTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block_test',
     'config_override_integration_test',
   ];
diff --git a/core/modules/config/tests/src/Functional/ConfigDependencyWebTest.php b/core/modules/config/tests/src/Functional/ConfigDependencyWebTest.php
index 696a36e8cb..052a2452d5 100644
--- a/core/modules/config/tests/src/Functional/ConfigDependencyWebTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigDependencyWebTest.php
@@ -22,7 +22,7 @@ class ConfigDependencyWebTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests ConfigDependencyDeleteFormTrait.
diff --git a/core/modules/config/tests/src/Functional/ConfigDraggableListBuilderTest.php b/core/modules/config/tests/src/Functional/ConfigDraggableListBuilderTest.php
index 74829359a1..8a604491dd 100644
--- a/core/modules/config/tests/src/Functional/ConfigDraggableListBuilderTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigDraggableListBuilderTest.php
@@ -15,7 +15,7 @@ class ConfigDraggableListBuilderTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Test draggable lists.
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php b/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
index a4dc92c78a..6e83d16ab9 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityFormOverrideTest.php
@@ -14,7 +14,7 @@ class ConfigEntityFormOverrideTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests that overrides do not affect forms or listing screens.
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityListMultilingualTest.php b/core/modules/config/tests/src/Functional/ConfigEntityListMultilingualTest.php
index 7c5fa1fac1..8f16b1ec4a 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityListMultilingualTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityListMultilingualTest.php
@@ -17,7 +17,7 @@ class ConfigEntityListMultilingualTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'language', 'block'];
+  protected static $modules = ['config_test', 'language', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityListTest.php b/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
index b92629d197..fe73372a5a 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityListTest.php
@@ -21,7 +21,7 @@ class ConfigEntityListTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'config_test'];
+  protected static $modules = ['block', 'config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityStatusUITest.php b/core/modules/config/tests/src/Functional/ConfigEntityStatusUITest.php
index af68f33bdc..4da9f8c751 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityStatusUITest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityStatusUITest.php
@@ -16,7 +16,7 @@ class ConfigEntityStatusUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests status operations.
diff --git a/core/modules/config/tests/src/Functional/ConfigEntityTest.php b/core/modules/config/tests/src/Functional/ConfigEntityTest.php
index 61669d9379..6f52b1dca4 100644
--- a/core/modules/config/tests/src/Functional/ConfigEntityTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigEntityTest.php
@@ -27,7 +27,7 @@ class ConfigEntityTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests CRUD operations.
diff --git a/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php b/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php
index 5ef146c8e4..6dc3d6f52d 100644
--- a/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php
+++ b/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php
@@ -66,7 +66,7 @@ class ConfigExportImportUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config', 'node', 'field'];
+  protected static $modules = ['config', 'node', 'field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/src/Functional/ConfigExportUITest.php b/core/modules/config/tests/src/Functional/ConfigExportUITest.php
index d92071e89d..4370dd0c4d 100644
--- a/core/modules/config/tests/src/Functional/ConfigExportUITest.php
+++ b/core/modules/config/tests/src/Functional/ConfigExportUITest.php
@@ -18,7 +18,7 @@ class ConfigExportUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config', 'config_test'];
+  protected static $modules = ['config', 'config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config/tests/src/Functional/ConfigImportInstallProfileTest.php b/core/modules/config/tests/src/Functional/ConfigImportInstallProfileTest.php
index 8b0787d6ee..190157c460 100644
--- a/core/modules/config/tests/src/Functional/ConfigImportInstallProfileTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigImportInstallProfileTest.php
@@ -23,7 +23,7 @@ class ConfigImportInstallProfileTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config'];
+  protected static $modules = ['config'];
 
   /**
    * A user with the 'synchronize configuration' permission.
diff --git a/core/modules/config/tests/src/Functional/ConfigImportUITest.php b/core/modules/config/tests/src/Functional/ConfigImportUITest.php
index 715976d162..2982969038 100644
--- a/core/modules/config/tests/src/Functional/ConfigImportUITest.php
+++ b/core/modules/config/tests/src/Functional/ConfigImportUITest.php
@@ -19,7 +19,7 @@ class ConfigImportUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config', 'config_test', 'config_import_test', 'text', 'options'];
+  protected static $modules = ['config', 'config_test', 'config_import_test', 'text', 'options'];
 
   /**
    * A user with the 'synchronize configuration' permission.
diff --git a/core/modules/config/tests/src/Functional/ConfigImportUploadTest.php b/core/modules/config/tests/src/Functional/ConfigImportUploadTest.php
index 6f6659d743..a1add2d636 100644
--- a/core/modules/config/tests/src/Functional/ConfigImportUploadTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigImportUploadTest.php
@@ -26,7 +26,7 @@ class ConfigImportUploadTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config'];
+  protected static $modules = ['config'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/config/tests/src/Functional/ConfigLanguageOverrideWebTest.php b/core/modules/config/tests/src/Functional/ConfigLanguageOverrideWebTest.php
index c7e0b27d44..2318c22756 100644
--- a/core/modules/config/tests/src/Functional/ConfigLanguageOverrideWebTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigLanguageOverrideWebTest.php
@@ -18,7 +18,7 @@ class ConfigLanguageOverrideWebTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'language',
     'system',
diff --git a/core/modules/config/tests/src/Functional/ConfigSingleImportExportTest.php b/core/modules/config/tests/src/Functional/ConfigSingleImportExportTest.php
index 69a7ed74ea..4b33643b7e 100644
--- a/core/modules/config/tests/src/Functional/ConfigSingleImportExportTest.php
+++ b/core/modules/config/tests/src/Functional/ConfigSingleImportExportTest.php
@@ -17,7 +17,7 @@ class ConfigSingleImportExportTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config',
     'config_test',
diff --git a/core/modules/config/tests/src/Functional/LanguageNegotiationFormOverrideTest.php b/core/modules/config/tests/src/Functional/LanguageNegotiationFormOverrideTest.php
index 6c4e1bb311..db5c45ce99 100644
--- a/core/modules/config/tests/src/Functional/LanguageNegotiationFormOverrideTest.php
+++ b/core/modules/config/tests/src/Functional/LanguageNegotiationFormOverrideTest.php
@@ -12,7 +12,7 @@
  */
 class LanguageNegotiationFormOverrideTest extends BrowserTestBase {
 
-  public static $modules = ['language', 'locale', 'locale_test'];
+  protected static $modules = ['language', 'locale', 'locale_test'];
 
   /**
    * Tests that overrides do not affect language-negotiation form values.
diff --git a/core/modules/config/tests/src/Functional/SchemaConfigListenerWebTest.php b/core/modules/config/tests/src/Functional/SchemaConfigListenerWebTest.php
index 189d78fc63..35270be09f 100644
--- a/core/modules/config/tests/src/Functional/SchemaConfigListenerWebTest.php
+++ b/core/modules/config/tests/src/Functional/SchemaConfigListenerWebTest.php
@@ -15,7 +15,7 @@ class SchemaConfigListenerWebTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests \Drupal\Core\Config\Development\ConfigSchemaChecker.
diff --git a/core/modules/config/tests/src/FunctionalJavascript/ConfigEntityTest.php b/core/modules/config/tests/src/FunctionalJavascript/ConfigEntityTest.php
index f7e6dc8ff5..01b67903a4 100644
--- a/core/modules/config/tests/src/FunctionalJavascript/ConfigEntityTest.php
+++ b/core/modules/config/tests/src/FunctionalJavascript/ConfigEntityTest.php
@@ -14,7 +14,7 @@ class ConfigEntityTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests ajax operations through the UI on 'Add' page.
diff --git a/core/modules/config/tests/src/Kernel/ConfigUninstallViaCliImportTest.php b/core/modules/config/tests/src/Kernel/ConfigUninstallViaCliImportTest.php
index 0ab0fd1764..ea307f1783 100644
--- a/core/modules/config/tests/src/Kernel/ConfigUninstallViaCliImportTest.php
+++ b/core/modules/config/tests/src/Kernel/ConfigUninstallViaCliImportTest.php
@@ -24,7 +24,7 @@ class ConfigUninstallViaCliImportTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'config'];
+  protected static $modules = ['system', 'config'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationCacheTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationCacheTest.php
index 0def24a490..40fcc70126 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationCacheTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationCacheTest.php
@@ -20,7 +20,7 @@ class ConfigTranslationCacheTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config_translation',
     'config_translation_test',
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationDateFormatUiTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationDateFormatUiTest.php
index 7cbeb57746..5a33fa9db6 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationDateFormatUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationDateFormatUiTest.php
@@ -12,7 +12,7 @@
  */
 class ConfigTranslationDateFormatUiTest extends BrowserTestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'language',
     'config_translation',
     'system',
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationFormTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationFormTest.php
index 4698b05a8e..aad24041ff 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationFormTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationFormTest.php
@@ -17,7 +17,7 @@ class ConfigTranslationFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_translation', 'config_translation_test', 'editor'];
+  protected static $modules = ['config_translation', 'config_translation_test', 'editor'];
 
   /**
    * The plugin ID of the mapper to test.
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
index 1d0116dc99..89586629fe 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
@@ -25,7 +25,7 @@ class ConfigTranslationListUiTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config_translation',
     'contact',
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationOverviewTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationOverviewTest.php
index 9ccbb135d2..19e41f481e 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationOverviewTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationOverviewTest.php
@@ -18,7 +18,7 @@ class ConfigTranslationOverviewTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config_test',
     'config_translation',
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php
index 64fde483e0..931f7acf19 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php
@@ -29,7 +29,7 @@ class ConfigTranslationUiTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config_translation',
     'config_translation_test',
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiThemeTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiThemeTest.php
index dcfb7916fe..609674283c 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiThemeTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiThemeTest.php
@@ -17,7 +17,7 @@ class ConfigTranslationUiThemeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_translation', 'config_translation_test'];
+  protected static $modules = ['config_translation', 'config_translation_test'];
 
   /**
    * Languages to enable.
diff --git a/core/modules/config_translation/tests/src/Functional/ConfigTranslationViewListUiTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationViewListUiTest.php
index edb41f9ad4..f035d46dbf 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationViewListUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationViewListUiTest.php
@@ -23,7 +23,7 @@ class ConfigTranslationViewListUiTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['config_translation', 'views_ui'];
+  protected static $modules = ['config_translation', 'views_ui'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/config_translation/tests/src/FunctionalJavascript/ConfigTranslationUiTest.php b/core/modules/config_translation/tests/src/FunctionalJavascript/ConfigTranslationUiTest.php
index 585d2d1d38..072a258b60 100644
--- a/core/modules/config_translation/tests/src/FunctionalJavascript/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/tests/src/FunctionalJavascript/ConfigTranslationUiTest.php
@@ -14,7 +14,7 @@ class ConfigTranslationUiTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'contextual',
     'node',
diff --git a/core/modules/config_translation/tests/src/Kernel/ConfigMapperTest.php b/core/modules/config_translation/tests/src/Kernel/ConfigMapperTest.php
index 773246cba9..aec2a2650d 100644
--- a/core/modules/config_translation/tests/src/Kernel/ConfigMapperTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/ConfigMapperTest.php
@@ -16,7 +16,7 @@ class ConfigMapperTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'config_translation_test',
     'language',
diff --git a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemMaintenanceTranslationTest.php b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemMaintenanceTranslationTest.php
index 26d68eed99..9a9fbc25ca 100644
--- a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemMaintenanceTranslationTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemMaintenanceTranslationTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateSystemMaintenanceTranslationTest extends MigrateDrupal6TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'language',
     'config_translation',
     // Required for translation migrations.
diff --git a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemSiteTranslationTest.php b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemSiteTranslationTest.php
index e420943264..a75c4ee91f 100644
--- a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemSiteTranslationTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateSystemSiteTranslationTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateSystemSiteTranslationTest extends MigrateDrupal6TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'language',
     'config_translation',
     // Required for translation migrations.
diff --git a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserConfigsTranslationTest.php b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserConfigsTranslationTest.php
index 5ff8402deb..6f6d1672bd 100644
--- a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserConfigsTranslationTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserConfigsTranslationTest.php
@@ -15,7 +15,7 @@ class MigrateUserConfigsTranslationTest extends MigrateDrupal6TestBase {
 
   use SchemaCheckTestTrait;
 
-  public static $modules = [
+  protected static $modules = [
     'language',
     'locale',
     'config_translation',
diff --git a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserProfileFieldInstanceTranslationTest.php b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserProfileFieldInstanceTranslationTest.php
index 033f22b9e8..af68ed678c 100644
--- a/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserProfileFieldInstanceTranslationTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Migrate/d6/MigrateUserProfileFieldInstanceTranslationTest.php
@@ -15,7 +15,7 @@ class MigrateUserProfileFieldInstanceTranslationTest extends MigrateDrupal6TestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'locale',
     'language',
diff --git a/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/I18nProfileFieldTest.php b/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/I18nProfileFieldTest.php
index c13a1b73f2..e3ec401ef4 100644
--- a/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/I18nProfileFieldTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/I18nProfileFieldTest.php
@@ -16,7 +16,7 @@ class I18nProfileFieldTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_translation', 'migrate_drupal', 'user'];
+  protected static $modules = ['config_translation', 'migrate_drupal', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldTranslationTest.php b/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldTranslationTest.php
index 3eb5880ed7..97d906ef20 100644
--- a/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldTranslationTest.php
+++ b/core/modules/config_translation/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldTranslationTest.php
@@ -15,7 +15,7 @@ class ProfileFieldTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_translation', 'migrate_drupal', 'user'];
+  protected static $modules = ['config_translation', 'migrate_drupal', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/ContactLanguageTest.php b/core/modules/contact/tests/src/Functional/ContactLanguageTest.php
index 0c34884503..79e1f791a3 100644
--- a/core/modules/contact/tests/src/Functional/ContactLanguageTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactLanguageTest.php
@@ -20,7 +20,7 @@ class ContactLanguageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'contact',
     'language',
     'contact_test',
diff --git a/core/modules/contact/tests/src/Functional/ContactPersonalTest.php b/core/modules/contact/tests/src/Functional/ContactPersonalTest.php
index 2a406eb8de..2c0b68f835 100644
--- a/core/modules/contact/tests/src/Functional/ContactPersonalTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactPersonalTest.php
@@ -25,7 +25,7 @@ class ContactPersonalTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['contact', 'dblog'];
+  protected static $modules = ['contact', 'dblog'];
 
   /**
    * A user with some administrative permissions.
diff --git a/core/modules/contact/tests/src/Functional/ContactSitewideTest.php b/core/modules/contact/tests/src/Functional/ContactSitewideTest.php
index 2c881b0180..375c7e1b91 100644
--- a/core/modules/contact/tests/src/Functional/ContactSitewideTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactSitewideTest.php
@@ -27,7 +27,7 @@ class ContactSitewideTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['text', 'contact', 'field_ui', 'contact_test', 'block', 'error_service_test', 'dblog'];
+  protected static $modules = ['text', 'contact', 'field_ui', 'contact_test', 'block', 'error_service_test', 'dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/ContactStorageTest.php b/core/modules/contact/tests/src/Functional/ContactStorageTest.php
index fbd938bb8a..7d8139ecde 100644
--- a/core/modules/contact/tests/src/Functional/ContactStorageTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactStorageTest.php
@@ -22,7 +22,7 @@ class ContactStorageTest extends ContactSitewideTest {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'text',
     'contact',
diff --git a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonAnonTest.php b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonAnonTest.php
index e863c978dd..9535509f72 100644
--- a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonAnonTest.php
+++ b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonAnonTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonBasicAuthTest.php
index 7280cfdc7e..a67f05a700 100644
--- a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonBasicAuthTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonCookieTest.php b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonCookieTest.php
index 2592ae7614..f7e96d6141 100644
--- a/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonCookieTest.php
+++ b/core/modules/contact/tests/src/Functional/Hal/ContactFormHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ContactFormHalJsonCookieTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonAnonTest.php b/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonAnonTest.php
index 088a872798..737dcbbd8c 100644
--- a/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonAnonTest.php
+++ b/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonAnonTest.php
@@ -17,7 +17,7 @@ class MessageHalJsonAnonTest extends MessageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonBasicAuthTest.php
index 363dbd7c87..80d569bafb 100644
--- a/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Hal/MessageHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MessageHalJsonBasicAuthTest extends MessageHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/ContactFormJsonBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Rest/ContactFormJsonBasicAuthTest.php
index 8e92a91009..e573b6d46e 100644
--- a/core/modules/contact/tests/src/Functional/Rest/ContactFormJsonBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Rest/ContactFormJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ContactFormJsonBasicAuthTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/ContactFormResourceTestBase.php b/core/modules/contact/tests/src/Functional/Rest/ContactFormResourceTestBase.php
index 98edc5ae91..f68f34e54b 100644
--- a/core/modules/contact/tests/src/Functional/Rest/ContactFormResourceTestBase.php
+++ b/core/modules/contact/tests/src/Functional/Rest/ContactFormResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/ContactFormXmlBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Rest/ContactFormXmlBasicAuthTest.php
index dfc4b6498a..cf520fc7b7 100644
--- a/core/modules/contact/tests/src/Functional/Rest/ContactFormXmlBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Rest/ContactFormXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ContactFormXmlBasicAuthTest extends ContactFormResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/MessageJsonBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Rest/MessageJsonBasicAuthTest.php
index f7f759ab90..f0dbc31f80 100644
--- a/core/modules/contact/tests/src/Functional/Rest/MessageJsonBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Rest/MessageJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MessageJsonBasicAuthTest extends MessageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/MessageResourceTestBase.php b/core/modules/contact/tests/src/Functional/Rest/MessageResourceTestBase.php
index f0ff8f85f9..e8c7dbeb54 100644
--- a/core/modules/contact/tests/src/Functional/Rest/MessageResourceTestBase.php
+++ b/core/modules/contact/tests/src/Functional/Rest/MessageResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Rest/MessageXmlBasicAuthTest.php b/core/modules/contact/tests/src/Functional/Rest/MessageXmlBasicAuthTest.php
index 152a94a86f..addcade4be 100644
--- a/core/modules/contact/tests/src/Functional/Rest/MessageXmlBasicAuthTest.php
+++ b/core/modules/contact/tests/src/Functional/Rest/MessageXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class MessageXmlBasicAuthTest extends MessageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php b/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php
index fd9b1ce8db..dca088561c 100644
--- a/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php
+++ b/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php
@@ -19,7 +19,7 @@ class ContactFieldsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'text', 'contact'];
+  protected static $modules = ['field', 'text', 'contact'];
 
   /**
    * Contains the field storage definition for contact used for this test.
diff --git a/core/modules/contact/tests/src/Functional/Views/ContactLinkTest.php b/core/modules/contact/tests/src/Functional/Views/ContactLinkTest.php
index c3b68f067a..7057d92ff7 100644
--- a/core/modules/contact/tests/src/Functional/Views/ContactLinkTest.php
+++ b/core/modules/contact/tests/src/Functional/Views/ContactLinkTest.php
@@ -27,7 +27,7 @@ class ContactLinkTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['contact_test_views'];
+  protected static $modules = ['contact_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/contact/tests/src/Kernel/MessageEntityTest.php b/core/modules/contact/tests/src/Kernel/MessageEntityTest.php
index e7343b9166..de556c0dc0 100644
--- a/core/modules/contact/tests/src/Kernel/MessageEntityTest.php
+++ b/core/modules/contact/tests/src/Kernel/MessageEntityTest.php
@@ -17,7 +17,7 @@ class MessageEntityTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'contact',
     'field',
diff --git a/core/modules/contact/tests/src/Kernel/Migrate/MigrateContactCategoryTest.php b/core/modules/contact/tests/src/Kernel/Migrate/MigrateContactCategoryTest.php
index ffadad409c..6eabda280f 100644
--- a/core/modules/contact/tests/src/Kernel/Migrate/MigrateContactCategoryTest.php
+++ b/core/modules/contact/tests/src/Kernel/Migrate/MigrateContactCategoryTest.php
@@ -18,7 +18,7 @@ class MigrateContactCategoryTest extends MigrateDrupal6TestBase {
    *
    * @var array
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Kernel/Migrate/d6/MigrateContactSettingsTest.php b/core/modules/contact/tests/src/Kernel/Migrate/d6/MigrateContactSettingsTest.php
index 073a670283..afadb04fc5 100644
--- a/core/modules/contact/tests/src/Kernel/Migrate/d6/MigrateContactSettingsTest.php
+++ b/core/modules/contact/tests/src/Kernel/Migrate/d6/MigrateContactSettingsTest.php
@@ -17,7 +17,7 @@ class MigrateContactSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Kernel/Migrate/d7/MigrateContactSettingsTest.php b/core/modules/contact/tests/src/Kernel/Migrate/d7/MigrateContactSettingsTest.php
index 22385f0e56..b94cdf0446 100644
--- a/core/modules/contact/tests/src/Kernel/Migrate/d7/MigrateContactSettingsTest.php
+++ b/core/modules/contact/tests/src/Kernel/Migrate/d7/MigrateContactSettingsTest.php
@@ -14,7 +14,7 @@ class MigrateContactSettingsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/ContactCategoryTest.php b/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/ContactCategoryTest.php
index 619e0cd10b..1ea9b337f2 100644
--- a/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/ContactCategoryTest.php
+++ b/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/ContactCategoryTest.php
@@ -15,7 +15,7 @@ class ContactCategoryTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact', 'migrate_drupal', 'user'];
+  protected static $modules = ['contact', 'migrate_drupal', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/d6/ContactSettingsTest.php b/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/d6/ContactSettingsTest.php
index 6d6afa36d3..1d29470984 100644
--- a/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/d6/ContactSettingsTest.php
+++ b/core/modules/contact/tests/src/Kernel/Plugin/migrate/source/d6/ContactSettingsTest.php
@@ -15,7 +15,7 @@ class ContactSettingsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact', 'migrate_drupal', 'user'];
+  protected static $modules = ['contact', 'migrate_drupal', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_moderation/tests/src/Functional/ContentModerationWorkflowTypeTest.php b/core/modules/content_moderation/tests/src/Functional/ContentModerationWorkflowTypeTest.php
index cbe5807a5f..7d08e4425e 100644
--- a/core/modules/content_moderation/tests/src/Functional/ContentModerationWorkflowTypeTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ContentModerationWorkflowTypeTest.php
@@ -16,7 +16,7 @@ class ContentModerationWorkflowTypeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'node',
     'entity_test',
diff --git a/core/modules/content_moderation/tests/src/Functional/ModeratedContentViewTest.php b/core/modules/content_moderation/tests/src/Functional/ModeratedContentViewTest.php
index 986fe125db..a1018a522a 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModeratedContentViewTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModeratedContentViewTest.php
@@ -24,7 +24,7 @@ class ModeratedContentViewTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['content_moderation', 'node', 'views'];
+  protected static $modules = ['content_moderation', 'node', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
index fbe0b3a38b..d3ead2949e 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
@@ -22,7 +22,7 @@ class ModerationActionsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'node',
     'views',
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php
index 9f3c401e63..d17b3d025b 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php
@@ -17,7 +17,7 @@ class ModerationFormTest extends ModerationStateTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'locale',
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php
index 28de50c535..5b83504845 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php
@@ -16,7 +16,7 @@ class ModerationLocaleTest extends ModerationStateTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'locale',
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php
index b1ad72045a..8c73f71283 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php
@@ -21,7 +21,7 @@ class ModerationRevisionRevertTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'node',
   ];
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php
index 86269193e3..54fcc4610f 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php
@@ -19,7 +19,7 @@ class ModerationStateAccessTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation_test_views',
     'content_moderation',
   ];
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php b/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php
index 9d12c17449..137ac85317 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php
@@ -61,7 +61,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'block',
     'block_content',
diff --git a/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php b/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php
index 76e9d97608..4c31760e4f 100644
--- a/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php
@@ -16,7 +16,7 @@ class NodeAccessTest extends ModerationStateTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'block',
     'block_content',
diff --git a/core/modules/content_moderation/tests/src/Functional/ViewsModerationStateFilterTest.php b/core/modules/content_moderation/tests/src/Functional/ViewsModerationStateFilterTest.php
index 12f391aea6..d0165c3cd9 100644
--- a/core/modules/content_moderation/tests/src/Functional/ViewsModerationStateFilterTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ViewsModerationStateFilterTest.php
@@ -23,7 +23,7 @@ class ViewsModerationStateFilterTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation_test_views',
     'node',
     'content_moderation',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationPermissionsTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationPermissionsTest.php
index b2abed2b01..506d870037 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationPermissionsTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationPermissionsTest.php
@@ -18,7 +18,7 @@ class ContentModerationPermissionsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'workflows',
     'content_moderation',
     'workflow_type_test',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateAccessControlHandlerTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateAccessControlHandlerTest.php
index 4d10672ada..f308f1f9b3 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateAccessControlHandlerTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateAccessControlHandlerTest.php
@@ -16,7 +16,7 @@ class ContentModerationStateAccessControlHandlerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'workflows',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateResourceTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateResourceTest.php
index 2ea1d8f901..c7538c1266 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateResourceTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateResourceTest.php
@@ -15,7 +15,7 @@ class ContentModerationStateResourceTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['serialization', 'rest', 'content_moderation'];
+  protected static $modules = ['serialization', 'rest', 'content_moderation'];
 
   /**
    * @see \Drupal\content_moderation\Entity\ContentModerationState
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
index c784b38b2c..63578c0754 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
@@ -21,7 +21,7 @@ class ContentModerationStateStorageSchemaTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php
index 8574ad6a17..c08b276bdd 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php
@@ -27,7 +27,7 @@ class ContentModerationStateTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'node',
     'block',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php
index a90c3fba96..1754f73088 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php
@@ -20,7 +20,7 @@ class ContentModerationWorkflowConfigTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowTypeApiTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowTypeApiTest.php
index 7c0e2fca95..0e03c7f86a 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowTypeApiTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowTypeApiTest.php
@@ -26,7 +26,7 @@ class ContentModerationWorkflowTypeApiTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'workflows',
     'content_moderation',
   ];
diff --git a/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php b/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php
index d24f7b5c80..46c4d7d698 100644
--- a/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php
@@ -20,7 +20,7 @@ class DefaultRevisionStateTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'node',
     'block_content',
diff --git a/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php b/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php
index 0a93924ab4..e4042d7c2b 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php
@@ -19,7 +19,7 @@ class EntityOperationsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'node',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php b/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php
index 69eee60d1a..2f8709f72a 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php
@@ -16,7 +16,7 @@ class EntityRevisionConverterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'user',
     'system',
     'content_moderation',
diff --git a/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php b/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
index dc1e7f6917..46a04f582e 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
@@ -19,7 +19,7 @@ class EntityStateChangeValidationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/EntityTypeInfoTest.php b/core/modules/content_moderation/tests/src/Kernel/EntityTypeInfoTest.php
index 09990fe796..aacd26ceb0 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityTypeInfoTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityTypeInfoTest.php
@@ -18,7 +18,7 @@ class EntityTypeInfoTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'workflows',
     'entity_test',
diff --git a/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php b/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php
index 1190aa0436..55b95768e2 100644
--- a/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php
@@ -20,7 +20,7 @@ class InitialStateTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'node',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ModerationInformationTest.php b/core/modules/content_moderation/tests/src/Kernel/ModerationInformationTest.php
index bff2a972a5..15ffdbace9 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationInformationTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationInformationTest.php
@@ -19,7 +19,7 @@ class ModerationInformationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'entity_test',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
index af0bb4fd7d..7a632d38c0 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
@@ -19,7 +19,7 @@ class ModerationStateFieldItemListTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'content_moderation',
     'user',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php b/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php
index f094964388..b73001065c 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php
@@ -23,7 +23,7 @@ class ModerationStateWidgetTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
     'workflows',
diff --git a/core/modules/content_moderation/tests/src/Kernel/NodeAccessTest.php b/core/modules/content_moderation/tests/src/Kernel/NodeAccessTest.php
index 3a2e0a9ed3..680e66ec92 100644
--- a/core/modules/content_moderation/tests/src/Kernel/NodeAccessTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/NodeAccessTest.php
@@ -29,7 +29,7 @@ class NodeAccessTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation',
     'filter',
     'node',
diff --git a/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php b/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
index 6d2b8b6b57..e36f57b04f 100644
--- a/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
@@ -21,7 +21,7 @@ class StateFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'workflows',
     'content_moderation',
     'entity_test',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php b/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php
index 0f89125bb6..2408dccdfa 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php
@@ -20,7 +20,7 @@ class ViewsDataIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation_test_views',
     'node',
     'content_moderation',
diff --git a/core/modules/content_moderation/tests/src/Kernel/ViewsModerationStateFilterTest.php b/core/modules/content_moderation/tests/src/Kernel/ViewsModerationStateFilterTest.php
index 32323cc13e..22ed6fb4a2 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ViewsModerationStateFilterTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ViewsModerationStateFilterTest.php
@@ -25,7 +25,7 @@ class ViewsModerationStateFilterTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation_test_views',
     'node',
     'content_moderation',
diff --git a/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php b/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
index a84bb73b8e..8f4dead228 100644
--- a/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
+++ b/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = ['text'];
+  protected static $modules = ['text'];
 
   /**
    * The entity type being tested.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTestTranslationUITest.php b/core/modules/content_translation/tests/src/Functional/ContentTestTranslationUITest.php
index 0b1de0b204..93f2eb1aca 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTestTranslationUITest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTestTranslationUITest.php
@@ -19,7 +19,7 @@ class ContentTestTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'entity_test'];
+  protected static $modules = ['language', 'content_translation', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationContextualLinksTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationContextualLinksTest.php
index b85c3aad5d..83c856264c 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationContextualLinksTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationContextualLinksTest.php
@@ -47,7 +47,7 @@ class ContentTranslationContextualLinksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['content_translation', 'contextual', 'node'];
+  protected static $modules = ['content_translation', 'contextual', 'node'];
 
   /**
    * The profile to install as a basis for testing.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationDisableSettingTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationDisableSettingTest.php
index 6dffed7444..d78b76f042 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationDisableSettingTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationDisableSettingTest.php
@@ -14,7 +14,7 @@ class ContentTranslationDisableSettingTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'menu_link_content',
     'language',
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationEnableTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationEnableTest.php
index a3cc4e9946..797bcfbf97 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationEnableTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationEnableTest.php
@@ -14,7 +14,7 @@ class ContentTranslationEnableTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'menu_link_content', 'node'];
+  protected static $modules = ['entity_test', 'menu_link_content', 'node'];
 
   /**
    * Tests that entity schemas are up-to-date after enabling translation.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationEntityBundleUITest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationEntityBundleUITest.php
index 163b5e8ff3..422ccb7299 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationEntityBundleUITest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationEntityBundleUITest.php
@@ -11,7 +11,7 @@
  */
 class ContentTranslationEntityBundleUITest extends BrowserTestBase {
 
-  public static $modules = ['language', 'content_translation', 'node', 'comment', 'field_ui'];
+  protected static $modules = ['language', 'content_translation', 'node', 'comment', 'field_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php
index 1bf836aaca..8fce666e8e 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php
@@ -22,7 +22,7 @@ class ContentTranslationLanguageChangeTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'content_translation_test', 'node', 'block', 'field_ui', 'image'];
+  protected static $modules = ['language', 'content_translation', 'content_translation_test', 'node', 'block', 'field_ui', 'image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationLinkTagTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationLinkTagTest.php
index 8ea652e954..0c8170d470 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationLinkTagTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationLinkTagTest.php
@@ -17,7 +17,7 @@ class ContentTranslationLinkTagTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'content_translation', 'content_translation_test', 'language'];
+  protected static $modules = ['entity_test', 'content_translation', 'content_translation_test', 'language'];
 
   /**
    * The added languages.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationMetadataFieldsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationMetadataFieldsTest.php
index bbad25ca9c..a3350f3ed7 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationMetadataFieldsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationMetadataFieldsTest.php
@@ -28,7 +28,7 @@ class ContentTranslationMetadataFieldsTest extends ContentTranslationTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'node'];
+  protected static $modules = ['language', 'content_translation', 'node'];
 
   /**
    * The profile to install as a basis for testing.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationOperationsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationOperationsTest.php
index 6eb3deb1c8..37ac1fb428 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationOperationsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationOperationsTest.php
@@ -32,7 +32,7 @@ class ContentTranslationOperationsTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'node', 'views', 'block'];
+  protected static $modules = ['language', 'content_translation', 'node', 'views', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationPendingRevisionTestBase.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationPendingRevisionTestBase.php
index 0984850f37..e989753666 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationPendingRevisionTestBase.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationPendingRevisionTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'content_translation', 'content_moderation', 'node'];
+  protected static $modules = ['language', 'content_translation', 'content_moderation', 'node'];
 
   /**
    * The entity storage.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationSettingsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationSettingsTest.php
index 52a9230007..e77d25d1b3 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationSettingsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationSettingsTest.php
@@ -24,7 +24,7 @@ class ContentTranslationSettingsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'node', 'comment', 'field_ui', 'entity_test'];
+  protected static $modules = ['language', 'content_translation', 'node', 'comment', 'field_ui', 'entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationStandardFieldsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationStandardFieldsTest.php
index c6a72a325e..19e02eda65 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationStandardFieldsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationStandardFieldsTest.php
@@ -16,7 +16,7 @@ class ContentTranslationStandardFieldsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'node',
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationSyncImageTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationSyncImageTest.php
index 5f7c9fd9b8..4910ef4a77 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationSyncImageTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationSyncImageTest.php
@@ -38,7 +38,7 @@ class ContentTranslationSyncImageTest extends ContentTranslationTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'entity_test', 'image', 'field_ui'];
+  protected static $modules = ['language', 'content_translation', 'entity_test', 'image', 'field_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php
index 82715c28c2..06911bb5c0 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['text'];
+  protected static $modules = ['text'];
 
   /**
    * The entity type being tested.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationUISkipTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationUISkipTest.php
index 97d0b00f5d..1d4645943c 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationUISkipTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationUISkipTest.php
@@ -16,7 +16,7 @@ class ContentTranslationUISkipTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['content_translation_test', 'user', 'node'];
+  protected static $modules = ['content_translation_test', 'user', 'node'];
 
   /**
    * Tests the content_translation_ui_skip key functionality.
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationUntranslatableFieldsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationUntranslatableFieldsTest.php
index 300c17c7ca..6cc33974a8 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationUntranslatableFieldsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationUntranslatableFieldsTest.php
@@ -17,7 +17,7 @@ class ContentTranslationUntranslatableFieldsTest extends ContentTranslationPendi
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
index c778404f64..d2510c18bb 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
@@ -29,7 +29,7 @@ class ContentTranslationWorkflowsTest extends ContentTranslationTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'entity_test'];
+  protected static $modules = ['language', 'content_translation', 'entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/content_translation/tests/src/Functional/Views/ContentTranslationViewsUITest.php b/core/modules/content_translation/tests/src/Functional/Views/ContentTranslationViewsUITest.php
index 4b4d53a484..d713c60687 100644
--- a/core/modules/content_translation/tests/src/Functional/Views/ContentTranslationViewsUITest.php
+++ b/core/modules/content_translation/tests/src/Functional/Views/ContentTranslationViewsUITest.php
@@ -23,7 +23,7 @@ class ContentTranslationViewsUITest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['content_translation'];
+  protected static $modules = ['content_translation'];
 
   /**
    * Tests the views UI.
diff --git a/core/modules/content_translation/tests/src/Functional/Views/TranslationLinkTest.php b/core/modules/content_translation/tests/src/Functional/Views/TranslationLinkTest.php
index d2e9e0d0cb..d75201ea5f 100644
--- a/core/modules/content_translation/tests/src/Functional/Views/TranslationLinkTest.php
+++ b/core/modules/content_translation/tests/src/Functional/Views/TranslationLinkTest.php
@@ -27,7 +27,7 @@ class TranslationLinkTest extends ContentTranslationTestBase {
    *
    * @var array
    */
-  public static $modules = ['content_translation_test_views'];
+  protected static $modules = ['content_translation_test_views'];
 
   protected function setUp() {
     // @todo Use entity_type once it is has multilingual Views integration.
diff --git a/core/modules/content_translation/tests/src/FunctionalJavascript/ContentTranslationContextualLinksTest.php b/core/modules/content_translation/tests/src/FunctionalJavascript/ContentTranslationContextualLinksTest.php
index 156b10d97f..3c6073244a 100644
--- a/core/modules/content_translation/tests/src/FunctionalJavascript/ContentTranslationContextualLinksTest.php
+++ b/core/modules/content_translation/tests/src/FunctionalJavascript/ContentTranslationContextualLinksTest.php
@@ -22,7 +22,7 @@ class ContentTranslationContextualLinksTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['content_translation', 'contextual', 'node'];
+  protected static $modules = ['content_translation', 'contextual', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Kernel/ContentTranslationConfigImportTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationConfigImportTest.php
index 0fe6b9f6e0..c14b293055 100644
--- a/core/modules/content_translation/tests/src/Kernel/ContentTranslationConfigImportTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/ContentTranslationConfigImportTest.php
@@ -25,7 +25,7 @@ class ContentTranslationConfigImportTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'entity_test', 'language', 'content_translation'];
+  protected static $modules = ['system', 'user', 'entity_test', 'language', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Kernel/ContentTranslationEntityBundleInfoTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationEntityBundleInfoTest.php
index dcd596ecf3..571a5c8de0 100644
--- a/core/modules/content_translation/tests/src/Kernel/ContentTranslationEntityBundleInfoTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/ContentTranslationEntityBundleInfoTest.php
@@ -16,7 +16,7 @@ class ContentTranslationEntityBundleInfoTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'language', 'content_translation_test', 'content_translation', 'entity_test'];
+  protected static $modules = ['user', 'language', 'content_translation_test', 'content_translation', 'entity_test'];
 
   /**
    * The content translation manager.
diff --git a/core/modules/content_translation/tests/src/Kernel/ContentTranslationFieldSyncRevisionTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationFieldSyncRevisionTest.php
index 8185182516..6c67c42400 100644
--- a/core/modules/content_translation/tests/src/Kernel/ContentTranslationFieldSyncRevisionTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/ContentTranslationFieldSyncRevisionTest.php
@@ -26,7 +26,7 @@ class ContentTranslationFieldSyncRevisionTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'image', 'language', 'content_translation', 'simpletest', 'content_translation_test'];
+  protected static $modules = ['file', 'image', 'language', 'content_translation', 'simpletest', 'content_translation_test'];
 
   /**
    * The synchronized field name.
diff --git a/core/modules/content_translation/tests/src/Kernel/ContentTranslationSettingsApiTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationSettingsApiTest.php
index 3626045fbf..40a7220a67 100644
--- a/core/modules/content_translation/tests/src/Kernel/ContentTranslationSettingsApiTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/ContentTranslationSettingsApiTest.php
@@ -16,7 +16,7 @@ class ContentTranslationSettingsApiTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'user', 'entity_test'];
+  protected static $modules = ['language', 'content_translation', 'user', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/content_translation/tests/src/Kernel/ContentTranslationSyncUnitTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationSyncUnitTest.php
index 5c4784aa62..d09b80abed 100644
--- a/core/modules/content_translation/tests/src/Kernel/ContentTranslationSyncUnitTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/ContentTranslationSyncUnitTest.php
@@ -54,7 +54,7 @@ class ContentTranslationSyncUnitTest extends KernelTestBase {
    */
   protected $unchangedFieldValues;
 
-  public static $modules = ['language', 'content_translation'];
+  protected static $modules = ['language', 'content_translation'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/content_translation/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php b/core/modules/content_translation/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
index 3e32406d28..02833902f7 100644
--- a/core/modules/content_translation/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
@@ -16,7 +16,7 @@ class MigrateTaxonomyTermTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/content_translation/tests/src/Kernel/Migrate/d7/MigrateEntityTranslationSettingsTest.php b/core/modules/content_translation/tests/src/Kernel/Migrate/d7/MigrateEntityTranslationSettingsTest.php
index 136e5331ec..41e6fa4032 100644
--- a/core/modules/content_translation/tests/src/Kernel/Migrate/d7/MigrateEntityTranslationSettingsTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/Migrate/d7/MigrateEntityTranslationSettingsTest.php
@@ -15,7 +15,7 @@ class MigrateEntityTranslationSettingsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'content_translation',
     'language',
diff --git a/core/modules/content_translation/tests/src/Kernel/Plugin/migrate/source/d7/EntityTranslationSettingsTest.php b/core/modules/content_translation/tests/src/Kernel/Plugin/migrate/source/d7/EntityTranslationSettingsTest.php
index db0d332927..7a25bf599d 100644
--- a/core/modules/content_translation/tests/src/Kernel/Plugin/migrate/source/d7/EntityTranslationSettingsTest.php
+++ b/core/modules/content_translation/tests/src/Kernel/Plugin/migrate/source/d7/EntityTranslationSettingsTest.php
@@ -16,7 +16,7 @@ class EntityTranslationSettingsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'migrate_drupal',
diff --git a/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php b/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
index 340b60821f..933dd0841c 100644
--- a/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
+++ b/core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
@@ -42,7 +42,7 @@ class ContextualDynamicContextTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['contextual', 'node', 'views', 'views_ui', 'language', 'menu_test'];
+  protected static $modules = ['contextual', 'node', 'views', 'views_ui', 'language', 'menu_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/contextual/tests/src/FunctionalJavascript/ContextualLinksTest.php b/core/modules/contextual/tests/src/FunctionalJavascript/ContextualLinksTest.php
index 7435dada23..9b3a1940b1 100644
--- a/core/modules/contextual/tests/src/FunctionalJavascript/ContextualLinksTest.php
+++ b/core/modules/contextual/tests/src/FunctionalJavascript/ContextualLinksTest.php
@@ -17,7 +17,7 @@ class ContextualLinksTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'contextual'];
+  protected static $modules = ['block', 'contextual'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/contextual/tests/src/FunctionalJavascript/EditModeTest.php b/core/modules/contextual/tests/src/FunctionalJavascript/EditModeTest.php
index 4a00a7efc4..8c9c9b4be8 100644
--- a/core/modules/contextual/tests/src/FunctionalJavascript/EditModeTest.php
+++ b/core/modules/contextual/tests/src/FunctionalJavascript/EditModeTest.php
@@ -19,7 +19,7 @@ class EditModeTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'block',
     'user',
diff --git a/core/modules/contextual/tests/src/Kernel/ContextualUnitTest.php b/core/modules/contextual/tests/src/Kernel/ContextualUnitTest.php
index 0e5f721375..84f5ba8c26 100644
--- a/core/modules/contextual/tests/src/Kernel/ContextualUnitTest.php
+++ b/core/modules/contextual/tests/src/Kernel/ContextualUnitTest.php
@@ -17,7 +17,7 @@ class ContextualUnitTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['contextual'];
+  protected static $modules = ['contextual'];
 
   /**
    * Provides testcases for testContextualLinksToId() and
diff --git a/core/modules/datetime/src/Tests/DateTestBase.php b/core/modules/datetime/src/Tests/DateTestBase.php
index 6a89003900..7b03f71f3a 100644
--- a/core/modules/datetime/src/Tests/DateTestBase.php
+++ b/core/modules/datetime/src/Tests/DateTestBase.php
@@ -25,7 +25,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'entity_test', 'datetime', 'field_ui'];
+  protected static $modules = ['node', 'entity_test', 'datetime', 'field_ui'];
 
   /**
    * An array of display options to pass to entity_get_display()
diff --git a/core/modules/datetime/src/Tests/Views/DateTimeHandlerTestBase.php b/core/modules/datetime/src/Tests/Views/DateTimeHandlerTestBase.php
index a89687ad15..e521ae6b22 100644
--- a/core/modules/datetime/src/Tests/Views/DateTimeHandlerTestBase.php
+++ b/core/modules/datetime/src/Tests/Views/DateTimeHandlerTestBase.php
@@ -22,7 +22,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['datetime_test', 'node', 'datetime'];
+  protected static $modules = ['datetime_test', 'node', 'datetime'];
 
   /**
    * Name of the field.
diff --git a/core/modules/datetime/tests/src/Functional/DateTestBase.php b/core/modules/datetime/tests/src/Functional/DateTestBase.php
index 46e23ce150..67f212caab 100644
--- a/core/modules/datetime/tests/src/Functional/DateTestBase.php
+++ b/core/modules/datetime/tests/src/Functional/DateTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'entity_test', 'datetime', 'field_ui'];
+  protected static $modules = ['node', 'entity_test', 'datetime', 'field_ui'];
 
   /**
    * An array of display options to pass to entity_get_display()
diff --git a/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDateonlyTest.php b/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDateonlyTest.php
index 0fb404d2b9..a4b30dcdf3 100644
--- a/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDateonlyTest.php
+++ b/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDateonlyTest.php
@@ -37,7 +37,7 @@ class EntityTestDateonlyTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['datetime', 'entity_test'];
+  protected static $modules = ['datetime', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDatetimeTest.php b/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDatetimeTest.php
index cdd4d605d0..a33a040a28 100644
--- a/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDatetimeTest.php
+++ b/core/modules/datetime/tests/src/Functional/EntityResource/EntityTest/EntityTestDatetimeTest.php
@@ -37,7 +37,7 @@ class EntityTestDatetimeTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['datetime', 'entity_test'];
+  protected static $modules = ['datetime', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/datetime/tests/src/Kernel/DateTimeFormInjectionTest.php b/core/modules/datetime/tests/src/Kernel/DateTimeFormInjectionTest.php
index a65d43928e..77c0d04c68 100644
--- a/core/modules/datetime/tests/src/Kernel/DateTimeFormInjectionTest.php
+++ b/core/modules/datetime/tests/src/Kernel/DateTimeFormInjectionTest.php
@@ -30,7 +30,7 @@ class DateTimeFormInjectionTest extends KernelTestBase implements FormInterface
    *
    * @var array
    */
-  public static $modules = ['system', 'datetime'];
+  protected static $modules = ['system', 'datetime'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php b/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
index 75f892a254..90768ffc1f 100644
--- a/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
+++ b/core/modules/datetime/tests/src/Kernel/DateTimeItemTest.php
@@ -37,7 +37,7 @@ class DateTimeItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['datetime'];
+  protected static $modules = ['datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php b/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php
index 5903551641..fe228f240f 100644
--- a/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php
+++ b/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php
@@ -19,7 +19,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['datetime_test', 'node', 'datetime', 'field'];
+  protected static $modules = ['datetime_test', 'node', 'datetime', 'field'];
 
   /**
    * Name of the field.
diff --git a/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php b/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php
index 9cecd605f0..17c0e81ddd 100644
--- a/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php
+++ b/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php
@@ -25,7 +25,7 @@ class DateRangeFieldTest extends DateTestBase {
    *
    * @var array
    */
-  public static $modules = ['datetime_range'];
+  protected static $modules = ['datetime_range'];
 
   /**
    * The default display settings to use for the formatters.
diff --git a/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php b/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php
index 658159a8aa..69a709a7cf 100644
--- a/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php
+++ b/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php
@@ -33,7 +33,7 @@ class DateRangeItemTest extends FieldKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'datetime',
     'datetime_range',
   ];
diff --git a/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php b/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php
index d92a313f39..09c1eeaf81 100644
--- a/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php
+++ b/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php
@@ -35,7 +35,7 @@ class SeparatorTranslationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'datetime',
     'datetime_range',
     'entity_test',
diff --git a/core/modules/datetime_range/tests/src/Kernel/Views/FilterDateTest.php b/core/modules/datetime_range/tests/src/Kernel/Views/FilterDateTest.php
index 76e3dbf447..085cbb8bb9 100644
--- a/core/modules/datetime_range/tests/src/Kernel/Views/FilterDateTest.php
+++ b/core/modules/datetime_range/tests/src/Kernel/Views/FilterDateTest.php
@@ -18,7 +18,7 @@ class FilterDateTest extends DateTimeHandlerTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['datetime_test', 'node', 'datetime_range', 'field'];
+  protected static $modules = ['datetime_test', 'node', 'datetime_range', 'field'];
 
   /**
    * Type of the field.
diff --git a/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php b/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php
index 37c855ae2c..0b951b6a56 100644
--- a/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php
+++ b/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php
@@ -12,7 +12,7 @@
  */
 class ConnectionFailureTest extends BrowserTestBase {
 
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * Tests logging of connection failures.
diff --git a/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php b/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
index 0d4630318e..624a567e95 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
@@ -39,7 +39,7 @@ class DbLogResourceTest extends ResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'dblog'];
+  protected static $modules = ['hal', 'dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/dblog/tests/src/Functional/DbLogTest.php b/core/modules/dblog/tests/src/Functional/DbLogTest.php
index 2b2f388cb2..5969fac3ec 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogTest.php
@@ -25,7 +25,7 @@ class DbLogTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['dblog', 'node', 'forum', 'help', 'block'];
+  protected static $modules = ['dblog', 'node', 'forum', 'help', 'block'];
 
   /**
    * A user with some relevant administrative permissions.
diff --git a/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php b/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
index 6e525cdf6f..f85e58c83f 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogViewsTest.php
@@ -19,7 +19,7 @@ class DbLogViewsTest extends DbLogTest {
    *
    * @var array
    */
-  public static $modules = ['dblog', 'node', 'forum', 'help', 'block', 'views'];
+  protected static $modules = ['dblog', 'node', 'forum', 'help', 'block', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/dblog/tests/src/Kernel/DbLogControllerTest.php b/core/modules/dblog/tests/src/Kernel/DbLogControllerTest.php
index ce7490f32e..26267c4b01 100644
--- a/core/modules/dblog/tests/src/Kernel/DbLogControllerTest.php
+++ b/core/modules/dblog/tests/src/Kernel/DbLogControllerTest.php
@@ -15,7 +15,7 @@ class DbLogControllerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['dblog', 'user'];
+  protected static $modules = ['dblog', 'user'];
 
   public function setUp() {
     parent::setUp();
diff --git a/core/modules/dblog/tests/src/Kernel/DbLogFormInjectionTest.php b/core/modules/dblog/tests/src/Kernel/DbLogFormInjectionTest.php
index 48ed39616e..31e1db253a 100644
--- a/core/modules/dblog/tests/src/Kernel/DbLogFormInjectionTest.php
+++ b/core/modules/dblog/tests/src/Kernel/DbLogFormInjectionTest.php
@@ -30,7 +30,7 @@ class DbLogFormInjectionTest extends KernelTestBase implements FormInterface {
    *
    * @var array
    */
-  public static $modules = ['system', 'dblog', 'user'];
+  protected static $modules = ['system', 'dblog', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/dblog/tests/src/Kernel/Migrate/d6/MigrateDblogConfigsTest.php b/core/modules/dblog/tests/src/Kernel/Migrate/d6/MigrateDblogConfigsTest.php
index 73a6d83d22..1e0cfd3b5a 100644
--- a/core/modules/dblog/tests/src/Kernel/Migrate/d6/MigrateDblogConfigsTest.php
+++ b/core/modules/dblog/tests/src/Kernel/Migrate/d6/MigrateDblogConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateDblogConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/dblog/tests/src/Kernel/Migrate/d7/MigrateDblogConfigsTest.php b/core/modules/dblog/tests/src/Kernel/Migrate/d7/MigrateDblogConfigsTest.php
index d9708309b2..ba94f66027 100644
--- a/core/modules/dblog/tests/src/Kernel/Migrate/d7/MigrateDblogConfigsTest.php
+++ b/core/modules/dblog/tests/src/Kernel/Migrate/d7/MigrateDblogConfigsTest.php
@@ -14,7 +14,7 @@ class MigrateDblogConfigsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php b/core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php
index daca0f64a5..653f3291ed 100644
--- a/core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php
+++ b/core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php
@@ -25,7 +25,7 @@ class ViewsIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['dblog', 'dblog_test_views', 'user'];
+  protected static $modules = ['dblog', 'dblog_test_views', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/EditorAdminTest.php b/core/modules/editor/tests/src/Functional/EditorAdminTest.php
index 3c0ab45082..8fc0385e72 100644
--- a/core/modules/editor/tests/src/Functional/EditorAdminTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorAdminTest.php
@@ -20,7 +20,7 @@ class EditorAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor'];
+  protected static $modules = ['filter', 'editor'];
 
   /**
    * A user with the 'administer filters' permission.
diff --git a/core/modules/editor/tests/src/Functional/EditorDialogAccessTest.php b/core/modules/editor/tests/src/Functional/EditorDialogAccessTest.php
index 3a97b351b3..06c3b9c860 100644
--- a/core/modules/editor/tests/src/Functional/EditorDialogAccessTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorDialogAccessTest.php
@@ -18,7 +18,7 @@ class EditorDialogAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['editor', 'filter', 'ckeditor'];
+  protected static $modules = ['editor', 'filter', 'ckeditor'];
 
   /**
    * Test access to the editor image dialog.
diff --git a/core/modules/editor/tests/src/Functional/EditorLoadingTest.php b/core/modules/editor/tests/src/Functional/EditorLoadingTest.php
index d0242140a3..8beb9e3621 100644
--- a/core/modules/editor/tests/src/Functional/EditorLoadingTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorLoadingTest.php
@@ -20,7 +20,7 @@ class EditorLoadingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'editor_test', 'node'];
+  protected static $modules = ['filter', 'editor', 'editor_test', 'node'];
 
   /**
    * An untrusted user, with access to the 'plain_text' format.
diff --git a/core/modules/editor/tests/src/Functional/EditorPrivateFileReferenceFilterTest.php b/core/modules/editor/tests/src/Functional/EditorPrivateFileReferenceFilterTest.php
index 4880c85fc8..1a2939b7ff 100644
--- a/core/modules/editor/tests/src/Functional/EditorPrivateFileReferenceFilterTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorPrivateFileReferenceFilterTest.php
@@ -19,7 +19,7 @@ class EditorPrivateFileReferenceFilterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     // Needed for the config: this is the only module in core that utilizes the
     // functionality in editor.module to be tested, and depends on that.
     'ckeditor',
diff --git a/core/modules/editor/tests/src/Functional/EditorSecurityTest.php b/core/modules/editor/tests/src/Functional/EditorSecurityTest.php
index 55095c98c6..6fefe590d5 100644
--- a/core/modules/editor/tests/src/Functional/EditorSecurityTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorSecurityTest.php
@@ -40,7 +40,7 @@ class EditorSecurityTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'editor', 'editor_test', 'node'];
+  protected static $modules = ['filter', 'editor', 'editor_test', 'node'];
 
   /**
    * User with access to Restricted HTML text format without text editor.
diff --git a/core/modules/editor/tests/src/Functional/EditorUploadImageScaleTest.php b/core/modules/editor/tests/src/Functional/EditorUploadImageScaleTest.php
index 46f9a6e458..fa58e4a7da 100644
--- a/core/modules/editor/tests/src/Functional/EditorUploadImageScaleTest.php
+++ b/core/modules/editor/tests/src/Functional/EditorUploadImageScaleTest.php
@@ -22,7 +22,7 @@ class EditorUploadImageScaleTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['editor', 'editor_test'];
+  protected static $modules = ['editor', 'editor_test'];
 
   /**
    * A user with permission as administer for testing.
diff --git a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonAnonTest.php b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonAnonTest.php
index 97d917d6dc..d08f466bc5 100644
--- a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonAnonTest.php
+++ b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EditorHalJsonAnonTest extends EditorResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonBasicAuthTest.php b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonBasicAuthTest.php
index 05f496bb6f..e9db80878e 100644
--- a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonBasicAuthTest.php
+++ b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EditorHalJsonBasicAuthTest extends EditorResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonCookieTest.php b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonCookieTest.php
index 4fe7ec9885..7b2afd7758 100644
--- a/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonCookieTest.php
+++ b/core/modules/editor/tests/src/Functional/Hal/EditorHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EditorHalJsonCookieTest extends EditorResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/QuickEditIntegrationLoadingTest.php b/core/modules/editor/tests/src/Functional/QuickEditIntegrationLoadingTest.php
index 6f96971bb7..89d0b1d91f 100644
--- a/core/modules/editor/tests/src/Functional/QuickEditIntegrationLoadingTest.php
+++ b/core/modules/editor/tests/src/Functional/QuickEditIntegrationLoadingTest.php
@@ -19,7 +19,7 @@ class QuickEditIntegrationLoadingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['quickedit', 'filter', 'node', 'editor'];
+  protected static $modules = ['quickedit', 'filter', 'node', 'editor'];
 
   /**
    * The basic permissions necessary to view content and use in-place editing.
diff --git a/core/modules/editor/tests/src/Functional/Rest/EditorJsonBasicAuthTest.php b/core/modules/editor/tests/src/Functional/Rest/EditorJsonBasicAuthTest.php
index f0c301030a..5bfa98b958 100644
--- a/core/modules/editor/tests/src/Functional/Rest/EditorJsonBasicAuthTest.php
+++ b/core/modules/editor/tests/src/Functional/Rest/EditorJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EditorJsonBasicAuthTest extends EditorResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/Rest/EditorResourceTestBase.php b/core/modules/editor/tests/src/Functional/Rest/EditorResourceTestBase.php
index 2dc43dc6a3..9c17974d30 100644
--- a/core/modules/editor/tests/src/Functional/Rest/EditorResourceTestBase.php
+++ b/core/modules/editor/tests/src/Functional/Rest/EditorResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ckeditor', 'editor'];
+  protected static $modules = ['ckeditor', 'editor'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Functional/Rest/EditorXmlBasicAuthTest.php b/core/modules/editor/tests/src/Functional/Rest/EditorXmlBasicAuthTest.php
index acab40b9a4..ae9f9d571d 100644
--- a/core/modules/editor/tests/src/Functional/Rest/EditorXmlBasicAuthTest.php
+++ b/core/modules/editor/tests/src/Functional/Rest/EditorXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EditorXmlBasicAuthTest extends EditorResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/editor/tests/src/Kernel/EditorFileReferenceFilterTest.php b/core/modules/editor/tests/src/Kernel/EditorFileReferenceFilterTest.php
index a70a232aa8..adc3e0b061 100644
--- a/core/modules/editor/tests/src/Kernel/EditorFileReferenceFilterTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorFileReferenceFilterTest.php
@@ -19,7 +19,7 @@ class EditorFileReferenceFilterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'filter', 'editor', 'field', 'file', 'user'];
+  protected static $modules = ['system', 'filter', 'editor', 'field', 'file', 'user'];
 
   /**
    * @var \Drupal\filter\Plugin\FilterInterface[]
diff --git a/core/modules/editor/tests/src/Kernel/EditorFileUsageTest.php b/core/modules/editor/tests/src/Kernel/EditorFileUsageTest.php
index aac665d61b..89ea85f4ac 100644
--- a/core/modules/editor/tests/src/Kernel/EditorFileUsageTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorFileUsageTest.php
@@ -23,7 +23,7 @@ class EditorFileUsageTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['editor', 'editor_test', 'node', 'file'];
+  protected static $modules = ['editor', 'editor_test', 'node', 'file'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php b/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php
index c7a9b9ad5b..66c238e73e 100644
--- a/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php
@@ -16,7 +16,7 @@ class EditorFilterIntegrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter', 'editor', 'editor_test'];
+  protected static $modules = ['filter', 'editor', 'editor_test'];
 
   /**
    * Tests text format removal or disabling.
diff --git a/core/modules/editor/tests/src/Kernel/EditorImageDialogTest.php b/core/modules/editor/tests/src/Kernel/EditorImageDialogTest.php
index 6500d1adef..9b59d400fb 100644
--- a/core/modules/editor/tests/src/Kernel/EditorImageDialogTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorImageDialogTest.php
@@ -28,7 +28,7 @@ class EditorImageDialogTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'file', 'editor', 'editor_test', 'user', 'system'];
+  protected static $modules = ['node', 'file', 'editor', 'editor_test', 'user', 'system'];
 
   /**
    * Sets up the test.
diff --git a/core/modules/editor/tests/src/Kernel/EditorManagerTest.php b/core/modules/editor/tests/src/Kernel/EditorManagerTest.php
index d1d6eafa18..f40f649072 100644
--- a/core/modules/editor/tests/src/Kernel/EditorManagerTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorManagerTest.php
@@ -18,7 +18,7 @@ class EditorManagerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'filter', 'editor'];
+  protected static $modules = ['system', 'user', 'filter', 'editor'];
 
   /**
    * The manager for text editor plugins.
diff --git a/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php b/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
index 1801cc8482..7d1bcde044 100644
--- a/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
+++ b/core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
@@ -26,7 +26,7 @@ class QuickEditIntegrationTest extends QuickEditTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['editor', 'editor_test'];
+  protected static $modules = ['editor', 'editor_test'];
 
   /**
    * The manager for editor plug-ins.
diff --git a/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
index 7a5e3ea4cc..61ccb346a0 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
@@ -27,7 +27,7 @@ class EntityReferenceAdminTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'path', 'taxonomy', 'block', 'views_ui'];
+  protected static $modules = ['node', 'field_ui', 'path', 'taxonomy', 'block', 'views_ui'];
 
   /**
    * The name of the content type created for testing purposes.
diff --git a/core/modules/field/src/Tests/Views/FieldTestBase.php b/core/modules/field/src/Tests/Views/FieldTestBase.php
index 01a884b8a7..bbfa52124e 100644
--- a/core/modules/field/src/Tests/Views/FieldTestBase.php
+++ b/core/modules/field/src/Tests/Views/FieldTestBase.php
@@ -32,7 +32,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test_views'];
+  protected static $modules = ['node', 'field_test_views'];
 
   /**
    * Stores the field definitions used by the test.
diff --git a/core/modules/field/tests/src/Functional/Boolean/BooleanFieldTest.php b/core/modules/field/tests/src/Functional/Boolean/BooleanFieldTest.php
index b1d7ab5298..ca93dbde62 100644
--- a/core/modules/field/tests/src/Functional/Boolean/BooleanFieldTest.php
+++ b/core/modules/field/tests/src/Functional/Boolean/BooleanFieldTest.php
@@ -19,7 +19,7 @@ class BooleanFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'field_ui',
     'options',
diff --git a/core/modules/field/tests/src/Functional/Boolean/BooleanFormatterSettingsTest.php b/core/modules/field/tests/src/Functional/Boolean/BooleanFormatterSettingsTest.php
index 0dadce9046..10c133bb79 100644
--- a/core/modules/field/tests/src/Functional/Boolean/BooleanFormatterSettingsTest.php
+++ b/core/modules/field/tests/src/Functional/Boolean/BooleanFormatterSettingsTest.php
@@ -18,7 +18,7 @@ class BooleanFormatterSettingsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
+  protected static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
 
   /**
    * The name of the entity bundle that is created in the test.
diff --git a/core/modules/field/tests/src/Functional/Email/EmailFieldTest.php b/core/modules/field/tests/src/Functional/Email/EmailFieldTest.php
index 76a167d117..d0948ef708 100644
--- a/core/modules/field/tests/src/Functional/Email/EmailFieldTest.php
+++ b/core/modules/field/tests/src/Functional/Email/EmailFieldTest.php
@@ -19,7 +19,7 @@ class EmailFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'entity_test', 'field_ui'];
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
 
   /**
    * A field storage to use in this test class.
diff --git a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
index 84f2b58a07..9f0564dd08 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
@@ -19,7 +19,7 @@ class EntityReferenceAutoCreateTest extends BrowserTestBase {
 
   use EntityReferenceTestTrait;
 
-  public static $modules = ['node', 'taxonomy'];
+  protected static $modules = ['node', 'taxonomy'];
 
   /**
    * The name of a content type that will reference $referencedType.
diff --git a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php
index f5d37c2d31..b40593030d 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php
@@ -22,7 +22,7 @@ class EntityReferenceFieldDefaultValueTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui', 'node'];
+  protected static $modules = ['field_ui', 'node'];
 
   /**
    * A user with permission to administer content types, node fields, etc.
diff --git a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldTranslatedReferenceViewTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldTranslatedReferenceViewTest.php
index cf53a7402a..8857f35f4b 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldTranslatedReferenceViewTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldTranslatedReferenceViewTest.php
@@ -118,7 +118,7 @@ class EntityReferenceFieldTranslatedReferenceViewTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'node',
diff --git a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFileUploadTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFileUploadTest.php
index 792f43576d..d42d29d3b5 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFileUploadTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFileUploadTest.php
@@ -17,7 +17,7 @@ class EntityReferenceFileUploadTest extends BrowserTestBase {
 
   use TestFileCreationTrait;
 
-  public static $modules = ['entity_reference', 'node', 'file'];
+  protected static $modules = ['entity_reference', 'node', 'file'];
 
   /**
    * The name of a content type that will reference $referencedType.
diff --git a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php
index 11e5b2813b..d9b377a79d 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php
@@ -45,7 +45,7 @@ class EntityReferenceIntegrationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'entity_test', 'field_ui'];
+  protected static $modules = ['config_test', 'entity_test', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php b/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
index 6e12a8e519..5890ffb899 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
@@ -14,7 +14,7 @@
  */
 class SelectionTest extends BrowserTestBase {
 
-  public static $modules = ['node', 'views', 'entity_reference_test', 'entity_test'];
+  protected static $modules = ['node', 'views', 'entity_reference_test', 'entity_test'];
 
   /**
    * Nodes for testing.
diff --git a/core/modules/field/tests/src/Functional/FieldAccessTest.php b/core/modules/field/tests/src/Functional/FieldAccessTest.php
index c7f234fd49..a7e4f7c36d 100644
--- a/core/modules/field/tests/src/Functional/FieldAccessTest.php
+++ b/core/modules/field/tests/src/Functional/FieldAccessTest.php
@@ -17,7 +17,7 @@ class FieldAccessTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test'];
+  protected static $modules = ['node', 'field_test'];
 
   /**
    * Node entity to use in this test.
diff --git a/core/modules/field/tests/src/Functional/FieldDefaultValueCallbackTest.php b/core/modules/field/tests/src/Functional/FieldDefaultValueCallbackTest.php
index 4a70e7171c..06e3cc5961 100644
--- a/core/modules/field/tests/src/Functional/FieldDefaultValueCallbackTest.php
+++ b/core/modules/field/tests/src/Functional/FieldDefaultValueCallbackTest.php
@@ -18,7 +18,7 @@ class FieldDefaultValueCallbackTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test', 'field_ui'];
+  protected static $modules = ['node', 'field_test', 'field_ui'];
 
   /**
    * The field name.
diff --git a/core/modules/field/tests/src/Functional/FieldHelpTest.php b/core/modules/field/tests/src/Functional/FieldHelpTest.php
index 712edec99a..bad4b68852 100644
--- a/core/modules/field/tests/src/Functional/FieldHelpTest.php
+++ b/core/modules/field/tests/src/Functional/FieldHelpTest.php
@@ -16,7 +16,7 @@ class FieldHelpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'help'];
+  protected static $modules = ['field', 'help'];
 
   // Tests field help implementation without optional core modules enabled.
   protected $profile = 'minimal';
diff --git a/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php b/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
index 6586446d5a..3a908ac991 100644
--- a/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
+++ b/core/modules/field/tests/src/Functional/FieldImportDeleteUninstallUiTest.php
@@ -22,7 +22,7 @@ class FieldImportDeleteUninstallUiTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'telephone', 'config', 'filter', 'datetime'];
+  protected static $modules = ['entity_test', 'telephone', 'config', 'filter', 'datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Functional/FormTest.php b/core/modules/field/tests/src/Functional/FormTest.php
index c1b135f043..668ce71f8e 100644
--- a/core/modules/field/tests/src/Functional/FormTest.php
+++ b/core/modules/field/tests/src/Functional/FormTest.php
@@ -25,7 +25,7 @@ class FormTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test', 'options', 'entity_test', 'locale'];
+  protected static $modules = ['node', 'field_test', 'options', 'entity_test', 'locale'];
 
   /**
    * An array of values defining a field single.
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonAnonTest.php b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonAnonTest.php
index 2137336c18..a94d6430c9 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonAnonTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class FieldConfigHalJsonAnonTest extends FieldConfigResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonBasicAuthTest.php b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonBasicAuthTest.php
index 8a299a4c49..ca4e9b0bf5 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class FieldConfigHalJsonBasicAuthTest extends FieldConfigResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonCookieTest.php b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonCookieTest.php
index c9f5ce0dd9..770c0462e0 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonCookieTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldConfigHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class FieldConfigHalJsonCookieTest extends FieldConfigResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonAnonTest.php b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonAnonTest.php
index 7e74390b38..3a1636c5d1 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonAnonTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class FieldStorageConfigHalJsonAnonTest extends FieldStorageConfigResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonBasicAuthTest.php b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonBasicAuthTest.php
index e3c2a3fb9c..65a77d6464 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class FieldStorageConfigHalJsonBasicAuthTest extends FieldStorageConfigResourceT
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonCookieTest.php b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonCookieTest.php
index 51df45617d..3359a86e93 100644
--- a/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonCookieTest.php
+++ b/core/modules/field/tests/src/Functional/Hal/FieldStorageConfigHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class FieldStorageConfigHalJsonCookieTest extends FieldStorageConfigResourceTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/NestedFormTest.php b/core/modules/field/tests/src/Functional/NestedFormTest.php
index bea6c51269..f5f4fc068b 100644
--- a/core/modules/field/tests/src/Functional/NestedFormTest.php
+++ b/core/modules/field/tests/src/Functional/NestedFormTest.php
@@ -18,7 +18,7 @@ class NestedFormTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test', 'entity_test'];
+  protected static $modules = ['field_test', 'entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Functional/Number/NumberFieldTest.php b/core/modules/field/tests/src/Functional/Number/NumberFieldTest.php
index c5f2bbe9f7..40ea4cc62c 100644
--- a/core/modules/field/tests/src/Functional/Number/NumberFieldTest.php
+++ b/core/modules/field/tests/src/Functional/Number/NumberFieldTest.php
@@ -18,7 +18,7 @@ class NumberFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'entity_test', 'field_ui'];
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldConfigJsonBasicAuthTest.php b/core/modules/field/tests/src/Functional/Rest/FieldConfigJsonBasicAuthTest.php
index d27354eac2..931325d02f 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldConfigJsonBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldConfigJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FieldConfigJsonBasicAuthTest extends FieldConfigResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldConfigResourceTestBase.php b/core/modules/field/tests/src/Functional/Rest/FieldConfigResourceTestBase.php
index 40ce43f578..e1ec9d3365 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldConfigResourceTestBase.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldConfigResourceTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'node'];
+  protected static $modules = ['field', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldConfigXmlBasicAuthTest.php b/core/modules/field/tests/src/Functional/Rest/FieldConfigXmlBasicAuthTest.php
index 109f2dc94a..c2e0d0d47b 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldConfigXmlBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldConfigXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class FieldConfigXmlBasicAuthTest extends FieldConfigResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonBasicAuthTest.php b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonBasicAuthTest.php
index 9aa875ab89..3dda429dd4 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FieldStorageConfigJsonBasicAuthTest extends FieldStorageConfigResourceTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigResourceTestBase.php b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigResourceTestBase.php
index 0d0fb6dd34..b9bd019975 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigResourceTestBase.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlBasicAuthTest.php b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlBasicAuthTest.php
index d6fe68f8e7..16bd5e725c 100644
--- a/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlBasicAuthTest.php
+++ b/core/modules/field/tests/src/Functional/Rest/FieldStorageConfigXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class FieldStorageConfigXmlBasicAuthTest extends FieldStorageConfigResourceTestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Functional/String/StringFieldTest.php b/core/modules/field/tests/src/Functional/String/StringFieldTest.php
index e9894f8103..14aa782c82 100644
--- a/core/modules/field/tests/src/Functional/String/StringFieldTest.php
+++ b/core/modules/field/tests/src/Functional/String/StringFieldTest.php
@@ -19,7 +19,7 @@ class StringFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'file'];
+  protected static $modules = ['entity_test', 'file'];
 
   /**
    * A user without any special permissions.
diff --git a/core/modules/field/tests/src/Functional/TranslationWebTest.php b/core/modules/field/tests/src/Functional/TranslationWebTest.php
index 465add964d..bf729bbb55 100644
--- a/core/modules/field/tests/src/Functional/TranslationWebTest.php
+++ b/core/modules/field/tests/src/Functional/TranslationWebTest.php
@@ -18,7 +18,7 @@ class TranslationWebTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'field_test', 'entity_test'];
+  protected static $modules = ['language', 'field_test', 'entity_test'];
 
   /**
    * The name of the field to use in this test.
diff --git a/core/modules/field/tests/src/Functional/Views/FieldTestBase.php b/core/modules/field/tests/src/Functional/Views/FieldTestBase.php
index 4b70fe2471..5978824fdd 100644
--- a/core/modules/field/tests/src/Functional/Views/FieldTestBase.php
+++ b/core/modules/field/tests/src/Functional/Views/FieldTestBase.php
@@ -25,7 +25,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test_views'];
+  protected static $modules = ['node', 'field_test_views'];
 
   /**
    * Stores the field definitions used by the test.
diff --git a/core/modules/field/tests/src/Functional/Views/FieldUITest.php b/core/modules/field/tests/src/Functional/Views/FieldUITest.php
index f43b30d662..9e5ee1d004 100644
--- a/core/modules/field/tests/src/Functional/Views/FieldUITest.php
+++ b/core/modules/field/tests/src/Functional/Views/FieldUITest.php
@@ -26,7 +26,7 @@ class FieldUITest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui'];
+  protected static $modules = ['views_ui'];
 
   /**
    * A user with the 'administer views' permission.
diff --git a/core/modules/field/tests/src/Functional/Views/HandlerFieldFieldTest.php b/core/modules/field/tests/src/Functional/Views/HandlerFieldFieldTest.php
index 7a14fb0571..7adb16e80b 100644
--- a/core/modules/field/tests/src/Functional/Views/HandlerFieldFieldTest.php
+++ b/core/modules/field/tests/src/Functional/Views/HandlerFieldFieldTest.php
@@ -22,7 +22,7 @@ class HandlerFieldFieldTest extends FieldTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'field_test'];
+  protected static $modules = ['node', 'field_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/field/tests/src/Functional/reEnableModuleFieldTest.php b/core/modules/field/tests/src/Functional/reEnableModuleFieldTest.php
index 59aaf22905..9ef3356031 100644
--- a/core/modules/field/tests/src/Functional/reEnableModuleFieldTest.php
+++ b/core/modules/field/tests/src/Functional/reEnableModuleFieldTest.php
@@ -21,7 +21,7 @@ class reEnableModuleFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'field',
     'node',
     // We use telephone module instead of test_field because test_field is
diff --git a/core/modules/field/tests/src/FunctionalJavascript/Boolean/BooleanFormatterSettingsTest.php b/core/modules/field/tests/src/FunctionalJavascript/Boolean/BooleanFormatterSettingsTest.php
index 7837536e27..ffdb4654ac 100644
--- a/core/modules/field/tests/src/FunctionalJavascript/Boolean/BooleanFormatterSettingsTest.php
+++ b/core/modules/field/tests/src/FunctionalJavascript/Boolean/BooleanFormatterSettingsTest.php
@@ -18,7 +18,7 @@ class BooleanFormatterSettingsTest extends WebDriverTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
+  protected static $modules = ['field', 'field_ui', 'text', 'node', 'user'];
 
   /**
    * The name of the entity bundle that is created in the test.
diff --git a/core/modules/field/tests/src/FunctionalJavascript/FormJSAddMoreTest.php b/core/modules/field/tests/src/FunctionalJavascript/FormJSAddMoreTest.php
index 0561d73711..152483fe42 100644
--- a/core/modules/field/tests/src/FunctionalJavascript/FormJSAddMoreTest.php
+++ b/core/modules/field/tests/src/FunctionalJavascript/FormJSAddMoreTest.php
@@ -18,7 +18,7 @@ class FormJSAddMoreTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_test', 'entity_test'];
+  protected static $modules = ['field_test', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php b/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php
index b2fb19384c..9ed4c6a3d9 100644
--- a/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php
@@ -21,7 +21,7 @@ class BooleanFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'text', 'entity_test', 'user', 'system'];
+  protected static $modules = ['field', 'text', 'entity_test', 'user', 'system'];
 
   /**
    * @var string
diff --git a/core/modules/field/tests/src/Kernel/DisplayApiTest.php b/core/modules/field/tests/src/Kernel/DisplayApiTest.php
index 3cbf63eb19..556c7890c0 100644
--- a/core/modules/field/tests/src/Kernel/DisplayApiTest.php
+++ b/core/modules/field/tests/src/Kernel/DisplayApiTest.php
@@ -59,7 +59,7 @@ class DisplayApiTest extends FieldKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Kernel/Entity/Update/SqlContentEntityStorageSchemaColumnTest.php b/core/modules/field/tests/src/Kernel/Entity/Update/SqlContentEntityStorageSchemaColumnTest.php
index 05db0dc5cc..3ad6a9a57f 100644
--- a/core/modules/field/tests/src/Kernel/Entity/Update/SqlContentEntityStorageSchemaColumnTest.php
+++ b/core/modules/field/tests/src/Kernel/Entity/Update/SqlContentEntityStorageSchemaColumnTest.php
@@ -18,7 +18,7 @@ class SqlContentEntityStorageSchemaColumnTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'field', 'text', 'user'];
+  protected static $modules = ['entity_test', 'field', 'text', 'user'];
 
   /**
    * The created entity.
diff --git a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
index 627fdba5dc..2d54ebf542 100644
--- a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
+++ b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
@@ -39,7 +39,7 @@ class EntityReferenceItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'file', 'taxonomy', 'text', 'filter', 'views', 'field'];
+  protected static $modules = ['node', 'comment', 'file', 'taxonomy', 'text', 'filter', 'views', 'field'];
 
   /**
    * The taxonomy vocabulary to test with.
diff --git a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php
index 93c39257b3..0b364be491 100644
--- a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php
@@ -23,7 +23,7 @@ class EntityReferenceSettingsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'taxonomy', 'field', 'user', 'text', 'entity_reference', 'entity_test', 'system'];
+  protected static $modules = ['node', 'taxonomy', 'field', 'user', 'text', 'entity_reference', 'entity_test', 'system'];
 
   /**
    * Testing node type.
diff --git a/core/modules/field/tests/src/Kernel/EntityReference/Views/EntityReferenceRelationshipTest.php b/core/modules/field/tests/src/Kernel/EntityReference/Views/EntityReferenceRelationshipTest.php
index 095e4bd8d8..11799bfb4a 100644
--- a/core/modules/field/tests/src/Kernel/EntityReference/Views/EntityReferenceRelationshipTest.php
+++ b/core/modules/field/tests/src/Kernel/EntityReference/Views/EntityReferenceRelationshipTest.php
@@ -41,7 +41,7 @@ class EntityReferenceRelationshipTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'field', 'entity_test', 'views', 'entity_reference_test_views'];
+  protected static $modules = ['user', 'field', 'entity_test', 'views', 'entity_reference_test_views'];
 
   /**
    * The entity_test entities used by the test.
diff --git a/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php b/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php
index afd468a5da..018aed2114 100644
--- a/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php
@@ -21,7 +21,7 @@ class FieldDefinitionIntegrityTest extends KernelTestBase {
   /**
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests the integrity of field plugin definitions.
diff --git a/core/modules/field/tests/src/Kernel/FieldDisplayTest.php b/core/modules/field/tests/src/Kernel/FieldDisplayTest.php
index beaa6e6b47..d6e3fe5a34 100644
--- a/core/modules/field/tests/src/Kernel/FieldDisplayTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldDisplayTest.php
@@ -20,7 +20,7 @@ class FieldDisplayTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'field',
     'system',
diff --git a/core/modules/field/tests/src/Kernel/FieldImportChangeTest.php b/core/modules/field/tests/src/Kernel/FieldImportChangeTest.php
index 9b8391961e..a8aac0d87a 100644
--- a/core/modules/field/tests/src/Kernel/FieldImportChangeTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldImportChangeTest.php
@@ -20,7 +20,7 @@ class FieldImportChangeTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test_config'];
+  protected static $modules = ['field_test_config'];
 
   /**
    * Tests importing an updated field.
diff --git a/core/modules/field/tests/src/Kernel/FieldImportDeleteTest.php b/core/modules/field/tests/src/Kernel/FieldImportDeleteTest.php
index b4180a0170..dff74601bc 100644
--- a/core/modules/field/tests/src/Kernel/FieldImportDeleteTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldImportDeleteTest.php
@@ -23,7 +23,7 @@ class FieldImportDeleteTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test_config'];
+  protected static $modules = ['field_test_config'];
 
   /**
    * Tests deleting field storages and fields as part of config import.
diff --git a/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php b/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
index c3a4d3c1d5..9ef64616c1 100644
--- a/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldImportDeleteUninstallTest.php
@@ -21,7 +21,7 @@ class FieldImportDeleteUninstallTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['telephone'];
+  protected static $modules = ['telephone'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php b/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
index 98d7419f5f..ba9f9c6f5a 100644
--- a/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
+++ b/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['user', 'system', 'field', 'text', 'entity_test', 'field_test'];
+  protected static $modules = ['user', 'system', 'field', 'text', 'entity_test', 'field_test'];
 
   /**
    * Bag of created field storages and fields.
diff --git a/core/modules/field/tests/src/Kernel/FieldStorageCrudTest.php b/core/modules/field/tests/src/Kernel/FieldStorageCrudTest.php
index 93c15a8347..7584f138d7 100644
--- a/core/modules/field/tests/src/Kernel/FieldStorageCrudTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldStorageCrudTest.php
@@ -21,7 +21,7 @@ class FieldStorageCrudTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   // TODO : test creation with
   // - a full fledged $field structure, check that all the values are there
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldFormatterSettingsTest.php b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldFormatterSettingsTest.php
index 7347c0470d..e64728acda 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldFormatterSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldFormatterSettingsTest.php
@@ -15,7 +15,7 @@ class MigrateFieldFormatterSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php
index 6c4e29c4be..67d56d7c3d 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php
@@ -17,7 +17,7 @@ class MigrateFieldInstanceTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * Tests migration of file variables to file.settings.yml.
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldWidgetSettingsTest.php b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldWidgetSettingsTest.php
index c6f47fb1bd..01c3efacdf 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldWidgetSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldWidgetSettingsTest.php
@@ -15,7 +15,7 @@ class MigrateFieldWidgetSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldFormatterSettingsTest.php b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldFormatterSettingsTest.php
index 6773ca8d28..71fa22b70a 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldFormatterSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldFormatterSettingsTest.php
@@ -17,7 +17,7 @@
  */
 class MigrateFieldFormatterSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'file',
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceTest.php b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceTest.php
index 35a5ff729a..f64355c105 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceTest.php
@@ -20,7 +20,7 @@ class MigrateFieldInstanceTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'file',
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceWidgetSettingsTest.php b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceWidgetSettingsTest.php
index 86e4f72510..d2dab17be9 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceWidgetSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldInstanceWidgetSettingsTest.php
@@ -18,7 +18,7 @@ class MigrateFieldInstanceWidgetSettingsTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'field',
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldTest.php b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldTest.php
index 14c6c31767..0e3d720de5 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldTest.php
@@ -18,7 +18,7 @@ class MigrateFieldTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'file',
diff --git a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateViewModesTest.php b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateViewModesTest.php
index 0a7e9dcc0d..27deaeccbc 100644
--- a/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateViewModesTest.php
+++ b/core/modules/field/tests/src/Kernel/Migrate/d7/MigrateViewModesTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateViewModesTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['comment', 'node', 'taxonomy'];
+  protected static $modules = ['comment', 'node', 'taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Number/NumberItemTest.php b/core/modules/field/tests/src/Kernel/Number/NumberItemTest.php
index ba47d91307..d885a038a5 100644
--- a/core/modules/field/tests/src/Kernel/Number/NumberItemTest.php
+++ b/core/modules/field/tests/src/Kernel/Number/NumberItemTest.php
@@ -21,7 +21,7 @@ class NumberItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerFormDisplayTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerFormDisplayTest.php
index dfbcc9f866..39619abc91 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerFormDisplayTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerFormDisplayTest.php
@@ -15,7 +15,7 @@ class FieldInstancePerFormDisplayTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerViewModeTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerViewModeTest.php
index baea562ee7..e46d00b15c 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerViewModeTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstancePerViewModeTest.php
@@ -15,7 +15,7 @@ class FieldInstancePerViewModeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal', 'node', 'user'];
+  protected static $modules = ['field', 'migrate_drupal', 'node', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstanceTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstanceTest.php
index bfbddcaef5..2fd757f771 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstanceTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldInstanceTest.php
@@ -15,7 +15,7 @@ class FieldInstanceTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldTest.php
index 06026414a0..e83d05e7c4 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d6/FieldTest.php
@@ -15,7 +15,7 @@ class FieldTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerFormDisplayTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerFormDisplayTest.php
index f0f1f0890d..0482ce8afd 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerFormDisplayTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerFormDisplayTest.php
@@ -15,7 +15,7 @@ class FieldInstancePerFormDisplayTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerViewModeTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerViewModeTest.php
index 1290264353..64c7d50ad9 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerViewModeTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstancePerViewModeTest.php
@@ -15,7 +15,7 @@ class FieldInstancePerViewModeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstanceTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstanceTest.php
index 942391ebd6..8cd0316603 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstanceTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldInstanceTest.php
@@ -15,7 +15,7 @@ class FieldInstanceTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldTest.php
index f904429d89..6be4de53d2 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/FieldTest.php
@@ -15,7 +15,7 @@ class FieldTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/ViewModeTest.php b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/ViewModeTest.php
index deab0668c9..15f6a4c521 100644
--- a/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/ViewModeTest.php
+++ b/core/modules/field/tests/src/Kernel/Plugin/migrate/source/d7/ViewModeTest.php
@@ -15,7 +15,7 @@ class ViewModeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'migrate_drupal'];
+  protected static $modules = ['field', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/ShapeItemTest.php b/core/modules/field/tests/src/Kernel/ShapeItemTest.php
index 80ab04f3a9..181e479c92 100644
--- a/core/modules/field/tests/src/Kernel/ShapeItemTest.php
+++ b/core/modules/field/tests/src/Kernel/ShapeItemTest.php
@@ -20,7 +20,7 @@ class ShapeItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * The name of the field to use in this test.
diff --git a/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php b/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php
index fba3bda6b5..7e40f995b0 100644
--- a/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php
@@ -22,7 +22,7 @@ class RawStringFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'text', 'entity_test', 'system', 'filter', 'user'];
+  protected static $modules = ['field', 'text', 'entity_test', 'system', 'filter', 'user'];
 
   /**
    * @var string
diff --git a/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php b/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php
index ae3a371c81..7c9c8adb6c 100644
--- a/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php
@@ -22,7 +22,7 @@ class StringFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'text', 'entity_test', 'system', 'filter', 'user'];
+  protected static $modules = ['field', 'text', 'entity_test', 'system', 'filter', 'user'];
 
   /**
    * @var string
diff --git a/core/modules/field/tests/src/Kernel/String/UuidFormatterTest.php b/core/modules/field/tests/src/Kernel/String/UuidFormatterTest.php
index 0eeb778076..4059cc6eb2 100644
--- a/core/modules/field/tests/src/Kernel/String/UuidFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/String/UuidFormatterTest.php
@@ -18,7 +18,7 @@ class UuidFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'entity_test', 'system', 'user'];
+  protected static $modules = ['field', 'entity_test', 'system', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/TestItemTest.php b/core/modules/field/tests/src/Kernel/TestItemTest.php
index 73a99486b6..a17401e3d9 100644
--- a/core/modules/field/tests/src/Kernel/TestItemTest.php
+++ b/core/modules/field/tests/src/Kernel/TestItemTest.php
@@ -21,7 +21,7 @@ class TestItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * The name of the field to use in this test.
diff --git a/core/modules/field/tests/src/Kernel/TestItemWithDependenciesTest.php b/core/modules/field/tests/src/Kernel/TestItemWithDependenciesTest.php
index 4e52b75965..60607c731e 100644
--- a/core/modules/field/tests/src/Kernel/TestItemWithDependenciesTest.php
+++ b/core/modules/field/tests/src/Kernel/TestItemWithDependenciesTest.php
@@ -17,7 +17,7 @@ class TestItemWithDependenciesTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * The name of the field to use in this test.
diff --git a/core/modules/field/tests/src/Kernel/TestObjectItemTest.php b/core/modules/field/tests/src/Kernel/TestObjectItemTest.php
index 1ac87fc3b7..0d5824030c 100644
--- a/core/modules/field/tests/src/Kernel/TestObjectItemTest.php
+++ b/core/modules/field/tests/src/Kernel/TestObjectItemTest.php
@@ -18,7 +18,7 @@ class TestObjectItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php b/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
index 9bb1f73acc..d1c83b5182 100644
--- a/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
@@ -20,7 +20,7 @@ class TimestampFormatterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'field', 'text', 'entity_test', 'user'];
+  protected static $modules = ['system', 'field', 'text', 'entity_test', 'user'];
 
   /**
    * @var string
diff --git a/core/modules/field/tests/src/Kernel/TranslationTest.php b/core/modules/field/tests/src/Kernel/TranslationTest.php
index 5d03f69171..31062db3a1 100644
--- a/core/modules/field/tests/src/Kernel/TranslationTest.php
+++ b/core/modules/field/tests/src/Kernel/TranslationTest.php
@@ -22,7 +22,7 @@ class TranslationTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node'];
+  protected static $modules = ['language', 'node'];
 
   /**
    * The name of the field to use in this test.
diff --git a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
index 9bab0b5431..01bc31346a 100644
--- a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
@@ -14,7 +14,7 @@ class FieldLayoutTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_layout', 'field_ui', 'node', 'field_layout_test'];
+  protected static $modules = ['field_layout', 'field_ui', 'node', 'field_layout_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
index 9e65b270be..8e28835fe1 100644
--- a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
@@ -15,7 +15,7 @@ class FieldLayoutTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_layout', 'field_ui', 'field_layout_test', 'layout_test'];
+  protected static $modules = ['field_layout', 'field_ui', 'field_layout_test', 'layout_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/src/Tests/FieldUIDeleteTest.php b/core/modules/field_ui/src/Tests/FieldUIDeleteTest.php
index 631d3368d0..73c588a944 100644
--- a/core/modules/field_ui/src/Tests/FieldUIDeleteTest.php
+++ b/core/modules/field_ui/src/Tests/FieldUIDeleteTest.php
@@ -22,7 +22,7 @@ class FieldUIDeleteTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'field_test', 'block', 'field_test_views'];
+  protected static $modules = ['node', 'field_ui', 'field_test', 'block', 'field_test_views'];
 
   /**
    * Test views to enable
diff --git a/core/modules/field_ui/src/Tests/ManageDisplayTest.php b/core/modules/field_ui/src/Tests/ManageDisplayTest.php
index 783e7fec21..24b0fbf052 100644
--- a/core/modules/field_ui/src/Tests/ManageDisplayTest.php
+++ b/core/modules/field_ui/src/Tests/ManageDisplayTest.php
@@ -24,7 +24,7 @@ class ManageDisplayTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'taxonomy', 'search', 'field_test', 'field_third_party_test', 'block'];
+  protected static $modules = ['node', 'field_ui', 'taxonomy', 'search', 'field_test', 'field_third_party_test', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/src/Tests/ManageFieldsTest.php b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
index bc7a2c54b9..2707dbdf00 100644
--- a/core/modules/field_ui/src/Tests/ManageFieldsTest.php
+++ b/core/modules/field_ui/src/Tests/ManageFieldsTest.php
@@ -26,7 +26,7 @@ class ManageFieldsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'field_test', 'taxonomy', 'image', 'block'];
+  protected static $modules = ['node', 'field_ui', 'field_test', 'taxonomy', 'image', 'block'];
 
   /**
    * The ID of the custom content type created for testing.
diff --git a/core/modules/field_ui/tests/src/Functional/EntityDisplayModeTest.php b/core/modules/field_ui/tests/src/Functional/EntityDisplayModeTest.php
index 953684193d..fc60848617 100644
--- a/core/modules/field_ui/tests/src/Functional/EntityDisplayModeTest.php
+++ b/core/modules/field_ui/tests/src/Functional/EntityDisplayModeTest.php
@@ -19,7 +19,7 @@ class EntityDisplayModeTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block', 'entity_test', 'field_ui', 'node'];
+  protected static $modules = ['block', 'entity_test', 'field_ui', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php b/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php
index c9cfc052ab..b9f7540449 100644
--- a/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php
+++ b/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php
@@ -14,7 +14,7 @@ class EntityDisplayTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_ui', 'entity_test'];
+  protected static $modules = ['field_ui', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Functional/FieldUIIndentationTest.php b/core/modules/field_ui/tests/src/Functional/FieldUIIndentationTest.php
index 1f66c9a772..b5d43c8464 100644
--- a/core/modules/field_ui/tests/src/Functional/FieldUIIndentationTest.php
+++ b/core/modules/field_ui/tests/src/Functional/FieldUIIndentationTest.php
@@ -16,7 +16,7 @@ class FieldUIIndentationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'field_ui_test'];
+  protected static $modules = ['node', 'field_ui', 'field_ui_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Functional/FieldUIRouteTest.php b/core/modules/field_ui/tests/src/Functional/FieldUIRouteTest.php
index fe7a27011c..0eb75e918e 100644
--- a/core/modules/field_ui/tests/src/Functional/FieldUIRouteTest.php
+++ b/core/modules/field_ui/tests/src/Functional/FieldUIRouteTest.php
@@ -18,7 +18,7 @@ class FieldUIRouteTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block', 'entity_test', 'field_ui'];
+  protected static $modules = ['block', 'entity_test', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Functional/ManageFieldsTest.php b/core/modules/field_ui/tests/src/Functional/ManageFieldsTest.php
index 1c21b069b4..a4566abe1b 100644
--- a/core/modules/field_ui/tests/src/Functional/ManageFieldsTest.php
+++ b/core/modules/field_ui/tests/src/Functional/ManageFieldsTest.php
@@ -14,7 +14,7 @@ class ManageFieldsTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'field_ui',
     'field_ui_test',
     'node',
diff --git a/core/modules/field_ui/tests/src/FunctionalJavascript/EntityDisplayTest.php b/core/modules/field_ui/tests/src/FunctionalJavascript/EntityDisplayTest.php
index 7909f0f006..1105c559c1 100644
--- a/core/modules/field_ui/tests/src/FunctionalJavascript/EntityDisplayTest.php
+++ b/core/modules/field_ui/tests/src/FunctionalJavascript/EntityDisplayTest.php
@@ -15,7 +15,7 @@ class EntityDisplayTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_ui', 'entity_test'];
+  protected static $modules = ['field_ui', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php b/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php
index 5ee2d406d2..46ef27161c 100644
--- a/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php
+++ b/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php
@@ -28,7 +28,7 @@ class EntityDisplayTest extends KernelTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['field_ui', 'field', 'entity_test', 'user', 'text', 'field_test', 'node', 'system'];
+  protected static $modules = ['field_ui', 'field', 'entity_test', 'user', 'text', 'field_test', 'node', 'system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/field_ui/tests/src/Kernel/EntityFormDisplayTest.php b/core/modules/field_ui/tests/src/Kernel/EntityFormDisplayTest.php
index c1d22b7423..3470a382c0 100644
--- a/core/modules/field_ui/tests/src/Kernel/EntityFormDisplayTest.php
+++ b/core/modules/field_ui/tests/src/Kernel/EntityFormDisplayTest.php
@@ -20,7 +20,7 @@ class EntityFormDisplayTest extends KernelTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['field_ui', 'field', 'entity_test', 'field_test', 'user', 'text'];
+  protected static $modules = ['field_ui', 'field', 'entity_test', 'field_test', 'user', 'text'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/src/Tests/FileFieldTestBase.php b/core/modules/file/src/Tests/FileFieldTestBase.php
index 0f82af3eac..d2683615b7 100644
--- a/core/modules/file/src/Tests/FileFieldTestBase.php
+++ b/core/modules/file/src/Tests/FileFieldTestBase.php
@@ -23,7 +23,7 @@
   *
   * @var array
   */
-  public static $modules = ['node', 'file', 'file_module_test', 'field_ui'];
+  protected static $modules = ['node', 'file', 'file_module_test', 'field_ui'];
 
   /**
    * An user with administration permissions.
diff --git a/core/modules/file/src/Tests/FileFieldWidgetTest.php b/core/modules/file/src/Tests/FileFieldWidgetTest.php
index 3102bd744d..c62f9970c9 100644
--- a/core/modules/file/src/Tests/FileFieldWidgetTest.php
+++ b/core/modules/file/src/Tests/FileFieldWidgetTest.php
@@ -37,7 +37,7 @@ protected function setUp() {
    *
    * @var array
    */
-  public static $modules = ['comment', 'block'];
+  protected static $modules = ['comment', 'block'];
 
   /**
    * Creates a temporary file, for a specific user.
diff --git a/core/modules/file/src/Tests/FileManagedTestBase.php b/core/modules/file/src/Tests/FileManagedTestBase.php
index 1c52b35312..c4fb78e007 100644
--- a/core/modules/file/src/Tests/FileManagedTestBase.php
+++ b/core/modules/file/src/Tests/FileManagedTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = ['file_test', 'file'];
+  protected static $modules = ['file_test', 'file'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/tests/src/Functional/FileFieldFormatterAccessTest.php b/core/modules/file/tests/src/Functional/FileFieldFormatterAccessTest.php
index 5fbbdf14ff..9bd0df7dd1 100644
--- a/core/modules/file/tests/src/Functional/FileFieldFormatterAccessTest.php
+++ b/core/modules/file/tests/src/Functional/FileFieldFormatterAccessTest.php
@@ -13,7 +13,7 @@ class FileFieldFormatterAccessTest extends FileFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'file', 'field_ui', 'file_test'];
+  protected static $modules = ['node', 'file', 'field_ui', 'file_test'];
 
   /**
    * Tests the custom access handler is invoked.
diff --git a/core/modules/file/tests/src/Functional/FileFieldRSSContentTest.php b/core/modules/file/tests/src/Functional/FileFieldRSSContentTest.php
index 26d14dbfb4..d2af48784a 100644
--- a/core/modules/file/tests/src/Functional/FileFieldRSSContentTest.php
+++ b/core/modules/file/tests/src/Functional/FileFieldRSSContentTest.php
@@ -16,7 +16,7 @@ class FileFieldRSSContentTest extends FileFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views'];
+  protected static $modules = ['node', 'views'];
 
   /**
    * Tests RSS enclosure formatter display for RSS feeds.
diff --git a/core/modules/file/tests/src/Functional/FileFieldTestBase.php b/core/modules/file/tests/src/Functional/FileFieldTestBase.php
index dc2e8becc1..5ae869cdca 100644
--- a/core/modules/file/tests/src/Functional/FileFieldTestBase.php
+++ b/core/modules/file/tests/src/Functional/FileFieldTestBase.php
@@ -24,7 +24,7 @@
   *
   * @var array
   */
-  public static $modules = ['node', 'file', 'file_module_test', 'field_ui'];
+  protected static $modules = ['node', 'file', 'file_module_test', 'field_ui'];
 
   /**
    * An user with administration permissions.
diff --git a/core/modules/file/tests/src/Functional/FileListingTest.php b/core/modules/file/tests/src/Functional/FileListingTest.php
index b1d39b3ad8..fe748c4db0 100644
--- a/core/modules/file/tests/src/Functional/FileListingTest.php
+++ b/core/modules/file/tests/src/Functional/FileListingTest.php
@@ -18,7 +18,7 @@ class FileListingTest extends FileFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'file', 'image', 'entity_test'];
+  protected static $modules = ['views', 'file', 'image', 'entity_test'];
 
   /**
    * An authenticated user.
diff --git a/core/modules/file/tests/src/Functional/FileManagedTestBase.php b/core/modules/file/tests/src/Functional/FileManagedTestBase.php
index e0da7d1a00..a15e666326 100644
--- a/core/modules/file/tests/src/Functional/FileManagedTestBase.php
+++ b/core/modules/file/tests/src/Functional/FileManagedTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['file_test', 'file'];
+  protected static $modules = ['file_test', 'file'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/tests/src/Functional/FileOnTranslatedEntityTest.php b/core/modules/file/tests/src/Functional/FileOnTranslatedEntityTest.php
index 2e22a69c35..cc4ae1d035 100644
--- a/core/modules/file/tests/src/Functional/FileOnTranslatedEntityTest.php
+++ b/core/modules/file/tests/src/Functional/FileOnTranslatedEntityTest.php
@@ -14,7 +14,7 @@ class FileOnTranslatedEntityTest extends FileFieldTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'content_translation'];
+  protected static $modules = ['language', 'content_translation'];
 
   /**
    * The name of the file field used in the test.
diff --git a/core/modules/file/tests/src/Functional/FilePrivateTest.php b/core/modules/file/tests/src/Functional/FilePrivateTest.php
index 2e5b0a1dac..db18ecc208 100644
--- a/core/modules/file/tests/src/Functional/FilePrivateTest.php
+++ b/core/modules/file/tests/src/Functional/FilePrivateTest.php
@@ -20,7 +20,7 @@ class FilePrivateTest extends FileFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test', 'field_test'];
+  protected static $modules = ['node_access_test', 'field_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/tests/src/Functional/FileUploadJsonBasicAuthTest.php b/core/modules/file/tests/src/Functional/FileUploadJsonBasicAuthTest.php
index cef59f83cf..03ce0d2a33 100644
--- a/core/modules/file/tests/src/Functional/FileUploadJsonBasicAuthTest.php
+++ b/core/modules/file/tests/src/Functional/FileUploadJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class FileUploadJsonBasicAuthTest extends FileUploadResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Hal/FileHalJsonAnonTest.php b/core/modules/file/tests/src/Functional/Hal/FileHalJsonAnonTest.php
index 6a1310078c..8a50ccdb32 100644
--- a/core/modules/file/tests/src/Functional/Hal/FileHalJsonAnonTest.php
+++ b/core/modules/file/tests/src/Functional/Hal/FileHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class FileHalJsonAnonTest extends FileResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Hal/FileHalJsonBasicAuthTest.php b/core/modules/file/tests/src/Functional/Hal/FileHalJsonBasicAuthTest.php
index 9101071728..691870c861 100644
--- a/core/modules/file/tests/src/Functional/Hal/FileHalJsonBasicAuthTest.php
+++ b/core/modules/file/tests/src/Functional/Hal/FileHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FileHalJsonBasicAuthTest extends FileHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonBasicAuthTest.php b/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonBasicAuthTest.php
index 647b85b9d6..0c325fe8d0 100644
--- a/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonBasicAuthTest.php
+++ b/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FileUploadHalJsonBasicAuthTest extends FileUploadHalJsonTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonTestBase.php b/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonTestBase.php
index 0b98c33f17..c0e0772030 100644
--- a/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonTestBase.php
+++ b/core/modules/file/tests/src/Functional/Hal/FileUploadHalJsonTestBase.php
@@ -15,7 +15,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/PrivateFileOnTranslatedEntityTest.php b/core/modules/file/tests/src/Functional/PrivateFileOnTranslatedEntityTest.php
index 7228e97a91..334c45a04d 100644
--- a/core/modules/file/tests/src/Functional/PrivateFileOnTranslatedEntityTest.php
+++ b/core/modules/file/tests/src/Functional/PrivateFileOnTranslatedEntityTest.php
@@ -15,7 +15,7 @@ class PrivateFileOnTranslatedEntityTest extends FileFieldTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'content_translation'];
+  protected static $modules = ['language', 'content_translation'];
 
   /**
    * The name of the file field used in the test.
diff --git a/core/modules/file/tests/src/Functional/RemoteFileSaveUploadTest.php b/core/modules/file/tests/src/Functional/RemoteFileSaveUploadTest.php
index e0e4be4b3c..f2e93b4cc5 100644
--- a/core/modules/file/tests/src/Functional/RemoteFileSaveUploadTest.php
+++ b/core/modules/file/tests/src/Functional/RemoteFileSaveUploadTest.php
@@ -14,7 +14,7 @@ class RemoteFileSaveUploadTest extends SaveUploadTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/tests/src/Functional/Rest/FileJsonBasicAuthTest.php b/core/modules/file/tests/src/Functional/Rest/FileJsonBasicAuthTest.php
index 87a65ac359..51caa2f08b 100644
--- a/core/modules/file/tests/src/Functional/Rest/FileJsonBasicAuthTest.php
+++ b/core/modules/file/tests/src/Functional/Rest/FileJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FileJsonBasicAuthTest extends FileResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Rest/FileResourceTestBase.php b/core/modules/file/tests/src/Functional/Rest/FileResourceTestBase.php
index 04b7c87ea3..7fb7b3e305 100644
--- a/core/modules/file/tests/src/Functional/Rest/FileResourceTestBase.php
+++ b/core/modules/file/tests/src/Functional/Rest/FileResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'user'];
+  protected static $modules = ['file', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/Rest/FileXmlBasicAuthTest.php b/core/modules/file/tests/src/Functional/Rest/FileXmlBasicAuthTest.php
index 66e9986dbc..f1c403db21 100644
--- a/core/modules/file/tests/src/Functional/Rest/FileXmlBasicAuthTest.php
+++ b/core/modules/file/tests/src/Functional/Rest/FileXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class FileXmlBasicAuthTest extends FileResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Functional/SaveUploadFormTest.php b/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
index e8b14e6ba1..9cf7c2bc75 100644
--- a/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
+++ b/core/modules/file/tests/src/Functional/SaveUploadFormTest.php
@@ -23,7 +23,7 @@ class SaveUploadFormTest extends FileManagedTestBase {
    *
    * @var array
    */
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * An image file path for uploading.
diff --git a/core/modules/file/tests/src/Functional/SaveUploadTest.php b/core/modules/file/tests/src/Functional/SaveUploadTest.php
index bebf47e076..da2bb569a6 100644
--- a/core/modules/file/tests/src/Functional/SaveUploadTest.php
+++ b/core/modules/file/tests/src/Functional/SaveUploadTest.php
@@ -21,7 +21,7 @@ class SaveUploadTest extends FileManagedTestBase {
    *
    * @var array
    */
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * An image file path for uploading.
diff --git a/core/modules/file/tests/src/Functional/Views/RelationshipUserFileDataTest.php b/core/modules/file/tests/src/Functional/Views/RelationshipUserFileDataTest.php
index 0169e0a6d8..2e384398a2 100644
--- a/core/modules/file/tests/src/Functional/Views/RelationshipUserFileDataTest.php
+++ b/core/modules/file/tests/src/Functional/Views/RelationshipUserFileDataTest.php
@@ -21,7 +21,7 @@ class RelationshipUserFileDataTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'file_test_views', 'user'];
+  protected static $modules = ['file', 'file_test_views', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php b/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
index 99acc3712a..2257e2e65e 100644
--- a/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
+++ b/core/modules/file/tests/src/FunctionalJavascript/FileFieldValidateTest.php
@@ -20,7 +20,7 @@ class FileFieldValidateTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'file'];
+  protected static $modules = ['node', 'file'];
 
   /**
    * Test the validation message is displayed only once for ajax uploads.
diff --git a/core/modules/file/tests/src/FunctionalJavascript/MaximumFileSizeExceededUploadTest.php b/core/modules/file/tests/src/FunctionalJavascript/MaximumFileSizeExceededUploadTest.php
index 45c8bf5eec..4c13e387a0 100644
--- a/core/modules/file/tests/src/FunctionalJavascript/MaximumFileSizeExceededUploadTest.php
+++ b/core/modules/file/tests/src/FunctionalJavascript/MaximumFileSizeExceededUploadTest.php
@@ -20,7 +20,7 @@ class MaximumFileSizeExceededUploadTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'file'];
+  protected static $modules = ['node', 'file'];
 
   /**
    * The file system service.
diff --git a/core/modules/file/tests/src/Kernel/AccessTest.php b/core/modules/file/tests/src/Kernel/AccessTest.php
index d875c1f664..8c0f4401c5 100644
--- a/core/modules/file/tests/src/Kernel/AccessTest.php
+++ b/core/modules/file/tests/src/Kernel/AccessTest.php
@@ -18,7 +18,7 @@ class AccessTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'system', 'user'];
+  protected static $modules = ['file', 'system', 'user'];
 
   /**
    * An authenticated user.
diff --git a/core/modules/file/tests/src/Kernel/FileItemTest.php b/core/modules/file/tests/src/Kernel/FileItemTest.php
index ac6cd8899f..2df20ef7e2 100644
--- a/core/modules/file/tests/src/Kernel/FileItemTest.php
+++ b/core/modules/file/tests/src/Kernel/FileItemTest.php
@@ -24,7 +24,7 @@ class FileItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * Created file entity.
diff --git a/core/modules/file/tests/src/Kernel/FileItemValidationTest.php b/core/modules/file/tests/src/Kernel/FileItemValidationTest.php
index ba763b6654..627e3f51ef 100644
--- a/core/modules/file/tests/src/Kernel/FileItemValidationTest.php
+++ b/core/modules/file/tests/src/Kernel/FileItemValidationTest.php
@@ -20,7 +20,7 @@ class FileItemValidationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'image', 'entity_test', 'field', 'user', 'system'];
+  protected static $modules = ['file', 'image', 'entity_test', 'field', 'user', 'system'];
 
   /**
    * A user.
diff --git a/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php b/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
index 7c43e9bfd0..d2952b44c9 100644
--- a/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
+++ b/core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['file_test', 'file', 'system', 'field', 'user'];
+  protected static $modules = ['file_test', 'file', 'system', 'field', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/file/tests/src/Kernel/Formatter/FileEntityFormatterTest.php b/core/modules/file/tests/src/Kernel/Formatter/FileEntityFormatterTest.php
index 743da8026e..a9234cb5eb 100644
--- a/core/modules/file/tests/src/Kernel/Formatter/FileEntityFormatterTest.php
+++ b/core/modules/file/tests/src/Kernel/Formatter/FileEntityFormatterTest.php
@@ -17,7 +17,7 @@ class FileEntityFormatterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'user'];
+  protected static $modules = ['file', 'user'];
 
   /**
    * The files.
diff --git a/core/modules/file/tests/src/Kernel/Migrate/MigrateFileStubTest.php b/core/modules/file/tests/src/Kernel/Migrate/MigrateFileStubTest.php
index 296508637b..9864ef9dc4 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/MigrateFileStubTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/MigrateFileStubTest.php
@@ -17,7 +17,7 @@ class MigrateFileStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityDisplayTest.php b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityDisplayTest.php
index 164168312d..da5c963af4 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityDisplayTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateUploadEntityDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityFormDisplayTest.php b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityFormDisplayTest.php
index 43a0ea6e47..daf69e877f 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityFormDisplayTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadEntityFormDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateUploadEntityFormDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadFieldTest.php b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadFieldTest.php
index 5032233873..0aadd3a4b7 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadFieldTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadFieldTest.php
@@ -15,7 +15,7 @@ class MigrateUploadFieldTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadInstanceTest.php b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadInstanceTest.php
index bf5807e68e..f1e1178b3a 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadInstanceTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadInstanceTest.php
@@ -15,7 +15,7 @@ class MigrateUploadInstanceTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadTest.php b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadTest.php
index b8075030bd..6e87ad9cbd 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d6/MigrateUploadTest.php
@@ -16,7 +16,7 @@ class MigrateUploadTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'menu_ui'];
+  protected static $modules = ['language', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php b/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
index ea32df5e34..dc42b2bbe8 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
@@ -17,7 +17,7 @@ class MigrateFileTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Migrate/d7/MigratePrivateFileTest.php b/core/modules/file/tests/src/Kernel/Migrate/d7/MigratePrivateFileTest.php
index 63e284ff98..1249df9273 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d7/MigratePrivateFileTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d7/MigratePrivateFileTest.php
@@ -17,7 +17,7 @@ class MigratePrivateFileTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/FileTest.php b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/FileTest.php
index 33c430e2fd..f316f9035e 100644
--- a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/FileTest.php
+++ b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/FileTest.php
@@ -16,7 +16,7 @@ class FileTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'migrate_drupal'];
+  protected static $modules = ['file', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadInstanceTest.php b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadInstanceTest.php
index 711b36fec3..e2d34b4f08 100644
--- a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadInstanceTest.php
+++ b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadInstanceTest.php
@@ -16,7 +16,7 @@ class UploadInstanceTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'migrate_drupal'];
+  protected static $modules = ['file', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadTest.php b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadTest.php
index 1f950b40cd..7d5a6cfa2c 100644
--- a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadTest.php
+++ b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d6/UploadTest.php
@@ -16,7 +16,7 @@ class UploadTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'migrate_drupal'];
+  protected static $modules = ['file', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d7/FileTest.php b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d7/FileTest.php
index b588ad789c..d5f76549f1 100644
--- a/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d7/FileTest.php
+++ b/core/modules/file/tests/src/Kernel/Plugin/migrate/source/d7/FileTest.php
@@ -15,7 +15,7 @@ class FileTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'migrate_drupal'];
+  protected static $modules = ['file', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/file/tests/src/Kernel/Views/ExtensionViewsFieldTest.php b/core/modules/file/tests/src/Kernel/Views/ExtensionViewsFieldTest.php
index 867ab7aaa1..ffed1eda96 100644
--- a/core/modules/file/tests/src/Kernel/Views/ExtensionViewsFieldTest.php
+++ b/core/modules/file/tests/src/Kernel/Views/ExtensionViewsFieldTest.php
@@ -18,7 +18,7 @@ class ExtensionViewsFieldTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'file_test_views', 'user'];
+  protected static $modules = ['file', 'file_test_views', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/file/tests/src/Kernel/Views/FileViewsFieldAccessTest.php b/core/modules/file/tests/src/Kernel/Views/FileViewsFieldAccessTest.php
index 539cb5d41f..419d22472b 100644
--- a/core/modules/file/tests/src/Kernel/Views/FileViewsFieldAccessTest.php
+++ b/core/modules/file/tests/src/Kernel/Views/FileViewsFieldAccessTest.php
@@ -17,7 +17,7 @@ class FileViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'entity_test', 'language', 'user'];
+  protected static $modules = ['file', 'entity_test', 'language', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/FilterAdminTest.php b/core/modules/filter/tests/src/Functional/FilterAdminTest.php
index d6327688ef..d4d6870195 100644
--- a/core/modules/filter/tests/src/Functional/FilterAdminTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterAdminTest.php
@@ -20,7 +20,7 @@ class FilterAdminTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'filter', 'node', 'filter_test_plugin', 'dblog'];
+  protected static $modules = ['block', 'filter', 'node', 'filter_test_plugin', 'dblog'];
 
   /**
    * An user with administration permissions.
diff --git a/core/modules/filter/tests/src/Functional/FilterCaptionTwigDebugTest.php b/core/modules/filter/tests/src/Functional/FilterCaptionTwigDebugTest.php
index f5423e7dd7..1f05c7fcb4 100644
--- a/core/modules/filter/tests/src/Functional/FilterCaptionTwigDebugTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterCaptionTwigDebugTest.php
@@ -18,7 +18,7 @@ class FilterCaptionTwigDebugTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'filter'];
+  protected static $modules = ['system', 'filter'];
 
   /**
    * @var \Drupal\filter\Plugin\FilterInterface[]
diff --git a/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php b/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php
index e5a57482a5..0ebc6dd71d 100644
--- a/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php
@@ -17,7 +17,7 @@ class FilterDefaultFormatTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * Tests if the default text format is accessible to users.
diff --git a/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php b/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php
index f82d258ddf..0be97d8593 100644
--- a/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php
@@ -19,7 +19,7 @@ class FilterFormatAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'filter', 'node'];
+  protected static $modules = ['block', 'filter', 'node'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/filter/tests/src/Functional/FilterHooksTest.php b/core/modules/filter/tests/src/Functional/FilterHooksTest.php
index 420a7b3855..1f54d6b824 100644
--- a/core/modules/filter/tests/src/Functional/FilterHooksTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterHooksTest.php
@@ -17,7 +17,7 @@ class FilterHooksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'filter_test'];
+  protected static $modules = ['node', 'filter_test'];
 
   /**
    * Tests hooks on format management.
diff --git a/core/modules/filter/tests/src/Functional/FilterHtmlImageSecureTest.php b/core/modules/filter/tests/src/Functional/FilterHtmlImageSecureTest.php
index 065d4a6f79..36c79eef16 100644
--- a/core/modules/filter/tests/src/Functional/FilterHtmlImageSecureTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterHtmlImageSecureTest.php
@@ -23,7 +23,7 @@ class FilterHtmlImageSecureTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'node', 'comment'];
+  protected static $modules = ['filter', 'node', 'comment'];
 
   /**
    * An authenticated user.
diff --git a/core/modules/filter/tests/src/Functional/FilterNoFormatTest.php b/core/modules/filter/tests/src/Functional/FilterNoFormatTest.php
index 19c57ac00f..f81ff22070 100644
--- a/core/modules/filter/tests/src/Functional/FilterNoFormatTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterNoFormatTest.php
@@ -16,7 +16,7 @@ class FilterNoFormatTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * Tests text without format.
diff --git a/core/modules/filter/tests/src/Functional/FilterSecurityTest.php b/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
index 4a5b7c49d2..8ffbced6f3 100644
--- a/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterSecurityTest.php
@@ -21,7 +21,7 @@ class FilterSecurityTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'filter_test'];
+  protected static $modules = ['node', 'filter_test'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonAnonTest.php b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonAnonTest.php
index 3a7c6335f5..e3d5e67d89 100644
--- a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonAnonTest.php
+++ b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class FilterFormatHalJsonAnonTest extends FilterFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonBasicAuthTest.php b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonBasicAuthTest.php
index c76293d9cc..3820dd6ed8 100644
--- a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonBasicAuthTest.php
+++ b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class FilterFormatHalJsonBasicAuthTest extends FilterFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonCookieTest.php b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonCookieTest.php
index d2a8654c59..052f604989 100644
--- a/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonCookieTest.php
+++ b/core/modules/filter/tests/src/Functional/Hal/FilterFormatHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class FilterFormatHalJsonCookieTest extends FilterFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/Rest/FilterFormatJsonBasicAuthTest.php b/core/modules/filter/tests/src/Functional/Rest/FilterFormatJsonBasicAuthTest.php
index 53ba6ce895..0a63f8fcbb 100644
--- a/core/modules/filter/tests/src/Functional/Rest/FilterFormatJsonBasicAuthTest.php
+++ b/core/modules/filter/tests/src/Functional/Rest/FilterFormatJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class FilterFormatJsonBasicAuthTest extends FilterFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/Rest/FilterFormatResourceTestBase.php b/core/modules/filter/tests/src/Functional/Rest/FilterFormatResourceTestBase.php
index 5a0174a65a..05a0c9fe19 100644
--- a/core/modules/filter/tests/src/Functional/Rest/FilterFormatResourceTestBase.php
+++ b/core/modules/filter/tests/src/Functional/Rest/FilterFormatResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Functional/Rest/FilterFormatXmlBasicAuthTest.php b/core/modules/filter/tests/src/Functional/Rest/FilterFormatXmlBasicAuthTest.php
index 6c0c62d52b..10a0bcd4f2 100644
--- a/core/modules/filter/tests/src/Functional/Rest/FilterFormatXmlBasicAuthTest.php
+++ b/core/modules/filter/tests/src/Functional/Rest/FilterFormatXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class FilterFormatXmlBasicAuthTest extends FilterFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Kernel/FilterAPITest.php b/core/modules/filter/tests/src/Kernel/FilterAPITest.php
index a26005db19..df0c778dd3 100644
--- a/core/modules/filter/tests/src/Kernel/FilterAPITest.php
+++ b/core/modules/filter/tests/src/Kernel/FilterAPITest.php
@@ -19,7 +19,7 @@
  */
 class FilterAPITest extends EntityKernelTestBase {
 
-  public static $modules = ['system', 'filter', 'filter_test', 'user'];
+  protected static $modules = ['system', 'filter', 'filter_test', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/filter/tests/src/Kernel/FilterCrudTest.php b/core/modules/filter/tests/src/Kernel/FilterCrudTest.php
index b73b180bfe..b544bcbea8 100644
--- a/core/modules/filter/tests/src/Kernel/FilterCrudTest.php
+++ b/core/modules/filter/tests/src/Kernel/FilterCrudTest.php
@@ -17,7 +17,7 @@ class FilterCrudTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'filter_test', 'system', 'user'];
+  protected static $modules = ['filter', 'filter_test', 'system', 'user'];
 
   /**
    * Tests CRUD operations for text formats and filters.
diff --git a/core/modules/filter/tests/src/Kernel/FilterDefaultConfigTest.php b/core/modules/filter/tests/src/Kernel/FilterDefaultConfigTest.php
index e16bddade5..57e5ea5982 100644
--- a/core/modules/filter/tests/src/Kernel/FilterDefaultConfigTest.php
+++ b/core/modules/filter/tests/src/Kernel/FilterDefaultConfigTest.php
@@ -13,7 +13,7 @@
  */
 class FilterDefaultConfigTest extends KernelTestBase {
 
-  public static $modules = ['system', 'user', 'filter', 'filter_test'];
+  protected static $modules = ['system', 'user', 'filter', 'filter_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/filter/tests/src/Kernel/FilterKernelTest.php b/core/modules/filter/tests/src/Kernel/FilterKernelTest.php
index b8626aedae..bf2d57125c 100644
--- a/core/modules/filter/tests/src/Kernel/FilterKernelTest.php
+++ b/core/modules/filter/tests/src/Kernel/FilterKernelTest.php
@@ -22,7 +22,7 @@ class FilterKernelTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'filter'];
+  protected static $modules = ['system', 'filter'];
 
   /**
    * @var \Drupal\filter\Plugin\FilterInterface[]
diff --git a/core/modules/filter/tests/src/Kernel/FilterSettingsTest.php b/core/modules/filter/tests/src/Kernel/FilterSettingsTest.php
index f77efac85a..047d7d63ef 100644
--- a/core/modules/filter/tests/src/Kernel/FilterSettingsTest.php
+++ b/core/modules/filter/tests/src/Kernel/FilterSettingsTest.php
@@ -17,7 +17,7 @@ class FilterSettingsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * Tests explicit and implicit default settings for filters.
diff --git a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
index 0f54245c1a..ac661763a0 100644
--- a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
+++ b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterFormatTest.php
@@ -16,7 +16,7 @@ class MigrateFilterFormatTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterSettingsTest.php b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterSettingsTest.php
index e58861dc03..7d27269b75 100644
--- a/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterSettingsTest.php
+++ b/core/modules/filter/tests/src/Kernel/Migrate/d7/MigrateFilterSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateFilterSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Kernel/Plugin/migrate/process/FilterIdTest.php b/core/modules/filter/tests/src/Kernel/Plugin/migrate/process/FilterIdTest.php
index eb5f7eacab..667fda394b 100644
--- a/core/modules/filter/tests/src/Kernel/Plugin/migrate/process/FilterIdTest.php
+++ b/core/modules/filter/tests/src/Kernel/Plugin/migrate/process/FilterIdTest.php
@@ -19,7 +19,7 @@ class FilterIdTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * The mocked MigrateExecutable.
diff --git a/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d6/FilterFormatTest.php b/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d6/FilterFormatTest.php
index a3e708b7b9..18448d1f6e 100644
--- a/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d6/FilterFormatTest.php
+++ b/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d6/FilterFormatTest.php
@@ -16,7 +16,7 @@ class FilterFormatTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter', 'migrate_drupal'];
+  protected static $modules = ['filter', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d7/FilterFormatTest.php b/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d7/FilterFormatTest.php
index 2dc9ce7c51..d2a2d48b5f 100644
--- a/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d7/FilterFormatTest.php
+++ b/core/modules/filter/tests/src/Kernel/Plugin/migrate/source/d7/FilterFormatTest.php
@@ -16,7 +16,7 @@ class FilterFormatTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter', 'migrate_drupal'];
+  protected static $modules = ['filter', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/filter/tests/src/Kernel/TextFormatElementFormTest.php b/core/modules/filter/tests/src/Kernel/TextFormatElementFormTest.php
index 8fca62e965..d4c8ed7c05 100644
--- a/core/modules/filter/tests/src/Kernel/TextFormatElementFormTest.php
+++ b/core/modules/filter/tests/src/Kernel/TextFormatElementFormTest.php
@@ -28,7 +28,7 @@ class TextFormatElementFormTest extends KernelTestBase implements FormInterface
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'filter', 'filter_test', 'editor'];
+  protected static $modules = ['system', 'user', 'filter', 'filter_test', 'editor'];
 
   /**
    * Sets up the test.
diff --git a/core/modules/forum/tests/src/Functional/ForumBlockTest.php b/core/modules/forum/tests/src/Functional/ForumBlockTest.php
index b231f6d0ea..d5105189e3 100644
--- a/core/modules/forum/tests/src/Functional/ForumBlockTest.php
+++ b/core/modules/forum/tests/src/Functional/ForumBlockTest.php
@@ -18,7 +18,7 @@ class ForumBlockTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['forum', 'block'];
+  protected static $modules = ['forum', 'block'];
 
   /**
    * A user with various administrative privileges.
diff --git a/core/modules/forum/tests/src/Functional/ForumIndexTest.php b/core/modules/forum/tests/src/Functional/ForumIndexTest.php
index 5d0ccdff3a..0fa3f7a670 100644
--- a/core/modules/forum/tests/src/Functional/ForumIndexTest.php
+++ b/core/modules/forum/tests/src/Functional/ForumIndexTest.php
@@ -16,7 +16,7 @@ class ForumIndexTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'comment', 'forum'];
+  protected static $modules = ['taxonomy', 'comment', 'forum'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/forum/tests/src/Functional/ForumNodeAccessTest.php b/core/modules/forum/tests/src/Functional/ForumNodeAccessTest.php
index 9849084c6c..9902fa88a7 100644
--- a/core/modules/forum/tests/src/Functional/ForumNodeAccessTest.php
+++ b/core/modules/forum/tests/src/Functional/ForumNodeAccessTest.php
@@ -17,7 +17,7 @@ class ForumNodeAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'forum', 'taxonomy', 'tracker', 'node_access_test', 'block'];
+  protected static $modules = ['node', 'comment', 'forum', 'taxonomy', 'tracker', 'node_access_test', 'block'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/forum/tests/src/Functional/ForumTest.php b/core/modules/forum/tests/src/Functional/ForumTest.php
index af331916b9..cf4ef5e7b5 100644
--- a/core/modules/forum/tests/src/Functional/ForumTest.php
+++ b/core/modules/forum/tests/src/Functional/ForumTest.php
@@ -25,7 +25,7 @@ class ForumTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'comment', 'forum', 'node', 'block', 'menu_ui', 'help'];
+  protected static $modules = ['taxonomy', 'comment', 'forum', 'node', 'block', 'menu_ui', 'help'];
 
   /**
    * A user with various administrative privileges.
diff --git a/core/modules/forum/tests/src/Functional/ForumUninstallTest.php b/core/modules/forum/tests/src/Functional/ForumUninstallTest.php
index c2d3848ffc..8b6bd4b647 100644
--- a/core/modules/forum/tests/src/Functional/ForumUninstallTest.php
+++ b/core/modules/forum/tests/src/Functional/ForumUninstallTest.php
@@ -21,7 +21,7 @@ class ForumUninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['forum'];
+  protected static $modules = ['forum'];
 
   /**
    * Tests if forum module uninstallation properly deletes the field.
diff --git a/core/modules/forum/tests/src/Functional/Views/ForumIntegrationTest.php b/core/modules/forum/tests/src/Functional/Views/ForumIntegrationTest.php
index 992500e1f9..909bd3ab98 100644
--- a/core/modules/forum/tests/src/Functional/Views/ForumIntegrationTest.php
+++ b/core/modules/forum/tests/src/Functional/Views/ForumIntegrationTest.php
@@ -19,7 +19,7 @@ class ForumIntegrationTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['forum_test_views'];
+  protected static $modules = ['forum_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/forum/tests/src/Kernel/ForumValidationTest.php b/core/modules/forum/tests/src/Kernel/ForumValidationTest.php
index 9b9661b5a2..2bbac72825 100644
--- a/core/modules/forum/tests/src/Kernel/ForumValidationTest.php
+++ b/core/modules/forum/tests/src/Kernel/ForumValidationTest.php
@@ -18,7 +18,7 @@ class ForumValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'options', 'comment', 'taxonomy', 'forum'];
+  protected static $modules = ['node', 'options', 'comment', 'taxonomy', 'forum'];
 
   /**
    * Tests the forum validation constraints.
diff --git a/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumConfigsTest.php b/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumConfigsTest.php
index 302c3d1aee..2bbc742e3c 100644
--- a/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumConfigsTest.php
+++ b/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateForumConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'forum', 'taxonomy'];
+  protected static $modules = ['comment', 'forum', 'taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumTest.php b/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumTest.php
index 6f5d48c1dd..d71441c142 100644
--- a/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumTest.php
+++ b/core/modules/forum/tests/src/Kernel/Migrate/d6/MigrateForumTest.php
@@ -19,7 +19,7 @@ class MigrateForumTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'forum',
     'menu_ui',
diff --git a/core/modules/forum/tests/src/Kernel/Migrate/d7/MigrateForumSettingsTest.php b/core/modules/forum/tests/src/Kernel/Migrate/d7/MigrateForumSettingsTest.php
index cd1c7fc3ea..891f3ae580 100644
--- a/core/modules/forum/tests/src/Kernel/Migrate/d7/MigrateForumSettingsTest.php
+++ b/core/modules/forum/tests/src/Kernel/Migrate/d7/MigrateForumSettingsTest.php
@@ -12,7 +12,7 @@
 class MigrateForumSettingsTest extends MigrateDrupal7TestBase {
 
   // Don't alphabetize these. They're in dependency order.
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'field',
     'filter',
diff --git a/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php b/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php
index 2ebff20247..fa049c8353 100644
--- a/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php
+++ b/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php
@@ -19,7 +19,7 @@ class EntityTranslationNormalizeTest extends NormalizerTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'content_translation'];
+  protected static $modules = ['node', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Kernel/FileNormalizeTest.php b/core/modules/hal/tests/src/Kernel/FileNormalizeTest.php
index edcf3dca1f..8f990564b9 100644
--- a/core/modules/hal/tests/src/Kernel/FileNormalizeTest.php
+++ b/core/modules/hal/tests/src/Kernel/FileNormalizeTest.php
@@ -16,7 +16,7 @@ class FileNormalizeTest extends NormalizerTestBase {
    *
    * @var array
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php b/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php
index 05a6b39f1e..35301b30a6 100644
--- a/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php
+++ b/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php
@@ -20,7 +20,7 @@ class HalLinkManagerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'hal_test', 'serialization', 'system', 'node', 'user', 'field'];
+  protected static $modules = ['hal', 'hal_test', 'serialization', 'system', 'node', 'user', 'field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Kernel/NormalizerTestBase.php b/core/modules/hal/tests/src/Kernel/NormalizerTestBase.php
index ef51a077c9..5eaa671711 100644
--- a/core/modules/hal/tests/src/Kernel/NormalizerTestBase.php
+++ b/core/modules/hal/tests/src/Kernel/NormalizerTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field', 'hal', 'language', 'serialization', 'system', 'text', 'user', 'filter'];
+  protected static $modules = ['entity_test', 'field', 'hal', 'language', 'serialization', 'system', 'text', 'user', 'filter'];
 
   /**
    * The mock serializer.
diff --git a/core/modules/help/tests/src/Functional/ExperimentalHelpTest.php b/core/modules/help/tests/src/Functional/ExperimentalHelpTest.php
index 0eabbda56b..b30d72f2d1 100644
--- a/core/modules/help/tests/src/Functional/ExperimentalHelpTest.php
+++ b/core/modules/help/tests/src/Functional/ExperimentalHelpTest.php
@@ -19,7 +19,7 @@ class ExperimentalHelpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['help', 'experimental_module_test', 'help_page_test'];
+  protected static $modules = ['help', 'experimental_module_test', 'help_page_test'];
 
   /**
    * The admin user.
diff --git a/core/modules/help/tests/src/Functional/HelpBlockTest.php b/core/modules/help/tests/src/Functional/HelpBlockTest.php
index 81c4fc1532..0354dc6055 100644
--- a/core/modules/help/tests/src/Functional/HelpBlockTest.php
+++ b/core/modules/help/tests/src/Functional/HelpBlockTest.php
@@ -14,7 +14,7 @@ class HelpBlockTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['help', 'help_page_test', 'block', 'more_help_page_test'];
+  protected static $modules = ['help', 'help_page_test', 'block', 'more_help_page_test'];
 
   /**
    * The help block instance.
diff --git a/core/modules/help/tests/src/Functional/HelpTest.php b/core/modules/help/tests/src/Functional/HelpTest.php
index 3965b53cde..bafbe19ba9 100644
--- a/core/modules/help/tests/src/Functional/HelpTest.php
+++ b/core/modules/help/tests/src/Functional/HelpTest.php
@@ -20,7 +20,7 @@ class HelpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['help_test', 'help_page_test'];
+  protected static $modules = ['help_test', 'help_page_test'];
 
   /**
    * Use the Standard profile to test help implementations of many core modules.
diff --git a/core/modules/help/tests/src/Functional/NoHelpTest.php b/core/modules/help/tests/src/Functional/NoHelpTest.php
index 5df945e35c..3b6b039949 100644
--- a/core/modules/help/tests/src/Functional/NoHelpTest.php
+++ b/core/modules/help/tests/src/Functional/NoHelpTest.php
@@ -18,7 +18,7 @@ class NoHelpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['help', 'menu_test'];
+  protected static $modules = ['help', 'menu_test'];
 
   /**
    * The user who will be created.
diff --git a/core/modules/help/tests/src/Kernel/HelpEmptyPageTest.php b/core/modules/help/tests/src/Kernel/HelpEmptyPageTest.php
index 070a95451b..542100eaad 100644
--- a/core/modules/help/tests/src/Kernel/HelpEmptyPageTest.php
+++ b/core/modules/help/tests/src/Kernel/HelpEmptyPageTest.php
@@ -17,7 +17,7 @@ class HelpEmptyPageTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'help_test', 'user'];
+  protected static $modules = ['system', 'help_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/history/tests/src/Functional/HistoryTest.php b/core/modules/history/tests/src/Functional/HistoryTest.php
index 415541ed60..b13e734c7d 100644
--- a/core/modules/history/tests/src/Functional/HistoryTest.php
+++ b/core/modules/history/tests/src/Functional/HistoryTest.php
@@ -21,7 +21,7 @@ class HistoryTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'history'];
+  protected static $modules = ['node', 'history'];
 
   /**
    * The main user for testing.
diff --git a/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
index 5aebaf43a1..e4b8ed3c3e 100644
--- a/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
+++ b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
@@ -21,7 +21,7 @@ class HistoryTimestampTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['history', 'node'];
+  protected static $modules = ['history', 'node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/image/src/Tests/ImageFieldTestBase.php b/core/modules/image/src/Tests/ImageFieldTestBase.php
index a1611cb352..6298f09f06 100644
--- a/core/modules/image/src/Tests/ImageFieldTestBase.php
+++ b/core/modules/image/src/Tests/ImageFieldTestBase.php
@@ -36,7 +36,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'image', 'field_ui', 'image_module_test'];
+  protected static $modules = ['node', 'image', 'field_ui', 'image_module_test'];
 
   /**
    * An user with permissions to administer content types and image styles.
diff --git a/core/modules/image/tests/src/Functional/FileMoveTest.php b/core/modules/image/tests/src/Functional/FileMoveTest.php
index 3cf3be71b8..f43e93aeff 100644
--- a/core/modules/image/tests/src/Functional/FileMoveTest.php
+++ b/core/modules/image/tests/src/Functional/FileMoveTest.php
@@ -24,7 +24,7 @@ class FileMoveTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * Tests moving a randomly generated image.
diff --git a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonAnonTest.php b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonAnonTest.php
index 61da51f7d0..cb61897da5 100644
--- a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonAnonTest.php
+++ b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ImageStyleHalJsonAnonTest extends ImageStyleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonBasicAuthTest.php b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonBasicAuthTest.php
index a6ff4941a3..7cb23a8924 100644
--- a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonBasicAuthTest.php
+++ b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ImageStyleHalJsonBasicAuthTest extends ImageStyleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonCookieTest.php b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonCookieTest.php
index 731e356c92..122b5684fc 100644
--- a/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonCookieTest.php
+++ b/core/modules/image/tests/src/Functional/Hal/ImageStyleHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ImageStyleHalJsonCookieTest extends ImageStyleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Functional/ImageDimensionsTest.php b/core/modules/image/tests/src/Functional/ImageDimensionsTest.php
index 4a11bf956e..7355fa0d2a 100644
--- a/core/modules/image/tests/src/Functional/ImageDimensionsTest.php
+++ b/core/modules/image/tests/src/Functional/ImageDimensionsTest.php
@@ -23,7 +23,7 @@ class ImageDimensionsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'image_module_test'];
+  protected static $modules = ['image', 'image_module_test'];
 
   protected $profile = 'testing';
 
diff --git a/core/modules/image/tests/src/Functional/ImageEffectsTest.php b/core/modules/image/tests/src/Functional/ImageEffectsTest.php
index f6b4ab36e9..df786e8f50 100644
--- a/core/modules/image/tests/src/Functional/ImageEffectsTest.php
+++ b/core/modules/image/tests/src/Functional/ImageEffectsTest.php
@@ -17,7 +17,7 @@ class ImageEffectsTest extends ToolkitTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'image_test', 'image_module_test'];
+  protected static $modules = ['image', 'image_test', 'image_module_test'];
 
   /**
    * The image effect manager.
diff --git a/core/modules/image/tests/src/Functional/ImageFieldDefaultImagesTest.php b/core/modules/image/tests/src/Functional/ImageFieldDefaultImagesTest.php
index 66899fb825..5f1149e723 100644
--- a/core/modules/image/tests/src/Functional/ImageFieldDefaultImagesTest.php
+++ b/core/modules/image/tests/src/Functional/ImageFieldDefaultImagesTest.php
@@ -29,7 +29,7 @@ class ImageFieldDefaultImagesTest extends ImageFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui'];
+  protected static $modules = ['field_ui'];
 
   /**
    * Tests CRUD for fields and field storages with default images.
diff --git a/core/modules/image/tests/src/Functional/ImageFieldDisplayTest.php b/core/modules/image/tests/src/Functional/ImageFieldDisplayTest.php
index ce924f426a..d4c617a990 100644
--- a/core/modules/image/tests/src/Functional/ImageFieldDisplayTest.php
+++ b/core/modules/image/tests/src/Functional/ImageFieldDisplayTest.php
@@ -29,7 +29,7 @@ class ImageFieldDisplayTest extends ImageFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui'];
+  protected static $modules = ['field_ui'];
 
   /**
    * Test image formatters on node display for public files.
diff --git a/core/modules/image/tests/src/Functional/ImageFieldTestBase.php b/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
index ef79de8503..7b4c514498 100644
--- a/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
+++ b/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
@@ -31,7 +31,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'image', 'field_ui', 'image_module_test'];
+  protected static $modules = ['node', 'image', 'field_ui', 'image_module_test'];
 
   /**
    * An user with permissions to administer content types and image styles.
diff --git a/core/modules/image/tests/src/Functional/ImageOnTranslatedEntityTest.php b/core/modules/image/tests/src/Functional/ImageOnTranslatedEntityTest.php
index 15ca758288..a902c016b4 100644
--- a/core/modules/image/tests/src/Functional/ImageOnTranslatedEntityTest.php
+++ b/core/modules/image/tests/src/Functional/ImageOnTranslatedEntityTest.php
@@ -20,7 +20,7 @@ class ImageOnTranslatedEntityTest extends ImageFieldTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'content_translation', 'field_ui'];
+  protected static $modules = ['language', 'content_translation', 'field_ui'];
 
   /**
    * The name of the image field used in the test.
diff --git a/core/modules/image/tests/src/Functional/ImageStylesPathAndUrlTest.php b/core/modules/image/tests/src/Functional/ImageStylesPathAndUrlTest.php
index c5b81e7ce3..4bea9c6e92 100644
--- a/core/modules/image/tests/src/Functional/ImageStylesPathAndUrlTest.php
+++ b/core/modules/image/tests/src/Functional/ImageStylesPathAndUrlTest.php
@@ -24,7 +24,7 @@ class ImageStylesPathAndUrlTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'image_module_test', 'language'];
+  protected static $modules = ['image', 'image_module_test', 'language'];
 
   /**
    * The image style.
diff --git a/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php b/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
index a037d4808d..57c38983c9 100644
--- a/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
+++ b/core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
@@ -22,7 +22,7 @@ class QuickEditImageControllerTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'image', 'quickedit'];
+  protected static $modules = ['node', 'image', 'quickedit'];
 
   /**
    * The machine name of our image field.
diff --git a/core/modules/image/tests/src/Functional/Rest/ImageStyleJsonBasicAuthTest.php b/core/modules/image/tests/src/Functional/Rest/ImageStyleJsonBasicAuthTest.php
index ab6ae57d53..02efc3b89f 100644
--- a/core/modules/image/tests/src/Functional/Rest/ImageStyleJsonBasicAuthTest.php
+++ b/core/modules/image/tests/src/Functional/Rest/ImageStyleJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ImageStyleJsonBasicAuthTest extends ImageStyleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Functional/Rest/ImageStyleResourceTestBase.php b/core/modules/image/tests/src/Functional/Rest/ImageStyleResourceTestBase.php
index a2a84312b8..451999dab6 100644
--- a/core/modules/image/tests/src/Functional/Rest/ImageStyleResourceTestBase.php
+++ b/core/modules/image/tests/src/Functional/Rest/ImageStyleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Functional/Rest/ImageStyleXmlBasicAuthTest.php b/core/modules/image/tests/src/Functional/Rest/ImageStyleXmlBasicAuthTest.php
index cd376a3140..cad07a265a 100644
--- a/core/modules/image/tests/src/Functional/Rest/ImageStyleXmlBasicAuthTest.php
+++ b/core/modules/image/tests/src/Functional/Rest/ImageStyleXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ImageStyleXmlBasicAuthTest extends ImageStyleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/FunctionalJavascript/ImageFieldTestBase.php b/core/modules/image/tests/src/FunctionalJavascript/ImageFieldTestBase.php
index 4e21f6aca7..efe566a19a 100644
--- a/core/modules/image/tests/src/FunctionalJavascript/ImageFieldTestBase.php
+++ b/core/modules/image/tests/src/FunctionalJavascript/ImageFieldTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'image',
     'field_ui',
diff --git a/core/modules/image/tests/src/FunctionalJavascript/QuickEditImageTest.php b/core/modules/image/tests/src/FunctionalJavascript/QuickEditImageTest.php
index b4444eff2b..eaf11a2b2d 100644
--- a/core/modules/image/tests/src/FunctionalJavascript/QuickEditImageTest.php
+++ b/core/modules/image/tests/src/FunctionalJavascript/QuickEditImageTest.php
@@ -20,7 +20,7 @@ class QuickEditImageTest extends QuickEditJavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'image', 'field_ui'];
+  protected static $modules = ['node', 'image', 'field_ui'];
 
   /**
    * A user with permissions to edit Articles and use Quick Edit.
diff --git a/core/modules/image/tests/src/Kernel/ImageFormatterTest.php b/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
index 1baa830199..52d61e9c53 100644
--- a/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
@@ -22,7 +22,7 @@ class ImageFormatterTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'image'];
+  protected static $modules = ['file', 'image'];
 
   /**
    * @var string
diff --git a/core/modules/image/tests/src/Kernel/ImageImportTest.php b/core/modules/image/tests/src/Kernel/ImageImportTest.php
index 9cf69570b6..5d013d3135 100644
--- a/core/modules/image/tests/src/Kernel/ImageImportTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageImportTest.php
@@ -15,7 +15,7 @@ class ImageImportTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'image', 'image_module_test'];
+  protected static $modules = ['system', 'image', 'image_module_test'];
 
   /**
    * Tests importing image styles.
diff --git a/core/modules/image/tests/src/Kernel/ImageItemTest.php b/core/modules/image/tests/src/Kernel/ImageItemTest.php
index 9621423823..aa41ec292a 100644
--- a/core/modules/image/tests/src/Kernel/ImageItemTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageItemTest.php
@@ -25,7 +25,7 @@ class ImageItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'image'];
+  protected static $modules = ['file', 'image'];
 
   /**
    * Created file entity.
diff --git a/core/modules/image/tests/src/Kernel/ImageStyleCustomStreamWrappersTest.php b/core/modules/image/tests/src/Kernel/ImageStyleCustomStreamWrappersTest.php
index 6a45a98680..89a82c4e50 100644
--- a/core/modules/image/tests/src/Kernel/ImageStyleCustomStreamWrappersTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageStyleCustomStreamWrappersTest.php
@@ -23,7 +23,7 @@ class ImageStyleCustomStreamWrappersTest extends KernelTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['system', 'image'];
+  protected static $modules = ['system', 'image'];
 
   /**
    * A testing image style entity.
diff --git a/core/modules/image/tests/src/Kernel/ImageStyleIntegrationTest.php b/core/modules/image/tests/src/Kernel/ImageStyleIntegrationTest.php
index e471c99164..09c9247bbb 100644
--- a/core/modules/image/tests/src/Kernel/ImageStyleIntegrationTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageStyleIntegrationTest.php
@@ -20,7 +20,7 @@ class ImageStyleIntegrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image', 'file', 'field', 'system', 'user', 'node'];
+  protected static $modules = ['image', 'file', 'field', 'system', 'user', 'node'];
 
   /**
    * Tests the dependency between ImageStyle and entity display components.
diff --git a/core/modules/image/tests/src/Kernel/ImageThemeFunctionTest.php b/core/modules/image/tests/src/Kernel/ImageThemeFunctionTest.php
index bffd6545f6..f44a5fdd6a 100644
--- a/core/modules/image/tests/src/Kernel/ImageThemeFunctionTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageThemeFunctionTest.php
@@ -29,7 +29,7 @@ class ImageThemeFunctionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field', 'file', 'image', 'system', 'simpletest', 'user'];
+  protected static $modules = ['entity_test', 'field', 'file', 'image', 'system', 'simpletest', 'user'];
 
   /**
    * Created file entity.
diff --git a/core/modules/image/tests/src/Kernel/Migrate/d6/MigrateImageTest.php b/core/modules/image/tests/src/Kernel/Migrate/d6/MigrateImageTest.php
index 7fc0b0bafb..2bb45b57f2 100644
--- a/core/modules/image/tests/src/Kernel/Migrate/d6/MigrateImageTest.php
+++ b/core/modules/image/tests/src/Kernel/Migrate/d6/MigrateImageTest.php
@@ -21,7 +21,7 @@ class MigrateImageTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageSettingsTest.php b/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageSettingsTest.php
index b95f0a2d58..bb8ee2c82f 100644
--- a/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageSettingsTest.php
+++ b/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateImageSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageStylesTest.php b/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageStylesTest.php
index a15d49e761..885ba7f0b3 100644
--- a/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageStylesTest.php
+++ b/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageStylesTest.php
@@ -17,7 +17,7 @@ class MigrateImageStylesTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d6/ImageCachePresetTest.php b/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d6/ImageCachePresetTest.php
index edd2ad3358..37abd1c2bc 100644
--- a/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d6/ImageCachePresetTest.php
+++ b/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d6/ImageCachePresetTest.php
@@ -16,7 +16,7 @@ class ImageCachePresetTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image', 'migrate_drupal'];
+  protected static $modules = ['image', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d7/ImageStylesTest.php b/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d7/ImageStylesTest.php
index 55251d1fb2..198e3af690 100644
--- a/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d7/ImageStylesTest.php
+++ b/core/modules/image/tests/src/Kernel/Plugin/migrate/source/d7/ImageStylesTest.php
@@ -16,7 +16,7 @@ class ImageStylesTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image', 'migrate_drupal'];
+  protected static $modules = ['image', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/image/tests/src/Kernel/Views/ImageViewsDataTest.php b/core/modules/image/tests/src/Kernel/Views/ImageViewsDataTest.php
index a324d5ead3..910661b53f 100644
--- a/core/modules/image/tests/src/Kernel/Views/ImageViewsDataTest.php
+++ b/core/modules/image/tests/src/Kernel/Views/ImageViewsDataTest.php
@@ -19,7 +19,7 @@ class ImageViewsDataTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'file', 'views', 'entity_test', 'user', 'field'];
+  protected static $modules = ['image', 'file', 'views', 'entity_test', 'user', 'field'];
 
   /**
    * Tests views data generated for image field relationship.
diff --git a/core/modules/image/tests/src/Kernel/Views/RelationshipUserImageDataTest.php b/core/modules/image/tests/src/Kernel/Views/RelationshipUserImageDataTest.php
index e0f605e92d..f24c79505b 100644
--- a/core/modules/image/tests/src/Kernel/Views/RelationshipUserImageDataTest.php
+++ b/core/modules/image/tests/src/Kernel/Views/RelationshipUserImageDataTest.php
@@ -22,7 +22,7 @@ class RelationshipUserImageDataTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'field', 'image', 'image_test_views', 'system', 'user'];
+  protected static $modules = ['file', 'field', 'image', 'image_test_views', 'system', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php b/core/modules/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php
index 9535c99fb2..ef160d13bf 100644
--- a/core/modules/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php
+++ b/core/modules/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php
@@ -19,7 +19,7 @@ class FormErrorHandlerFileUploadTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'file', 'field_ui', 'inline_form_errors'];
+  protected static $modules = ['node', 'file', 'field_ui', 'inline_form_errors'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
index 7c9a74ab50..ad5498576b 100644
--- a/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
+++ b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerCKEditorTest.php
@@ -20,7 +20,7 @@ class FormErrorHandlerCKEditorTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'ckeditor', 'inline_form_errors', 'filter'];
+  protected static $modules = ['node', 'ckeditor', 'inline_form_errors', 'filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerQuickEditTest.php b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerQuickEditTest.php
index 00dc3d3f62..1109c2dccb 100644
--- a/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerQuickEditTest.php
+++ b/core/modules/inline_form_errors/tests/src/FunctionalJavascript/FormErrorHandlerQuickEditTest.php
@@ -17,7 +17,7 @@ class FormErrorHandlerQuickEditTest extends WebDriverTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'quickedit',
     'node',
     'inline_form_errors',
diff --git a/core/modules/inline_form_errors/tests/src/Kernel/FormElementInlineErrorTest.php b/core/modules/inline_form_errors/tests/src/Kernel/FormElementInlineErrorTest.php
index 4bf389e60f..8ce31a2fe9 100644
--- a/core/modules/inline_form_errors/tests/src/Kernel/FormElementInlineErrorTest.php
+++ b/core/modules/inline_form_errors/tests/src/Kernel/FormElementInlineErrorTest.php
@@ -15,7 +15,7 @@ class FormElementInlineErrorTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['inline_form_errors'];
+  protected static $modules = ['inline_form_errors'];
 
   /**
    * Tests that no inline form errors are shown when disabled for a form.
diff --git a/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php b/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php
index f689a9233f..034e7ab225 100644
--- a/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php
+++ b/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php
@@ -12,7 +12,7 @@
  */
 class AdminPathEntityConverterLanguageTest extends BrowserTestBase {
 
-  public static $modules = ['language', 'language_test'];
+  protected static $modules = ['language', 'language_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Functional/EntityTypeWithoutLanguageFormTest.php b/core/modules/language/tests/src/Functional/EntityTypeWithoutLanguageFormTest.php
index f7b6191484..12739f45a4 100644
--- a/core/modules/language/tests/src/Functional/EntityTypeWithoutLanguageFormTest.php
+++ b/core/modules/language/tests/src/Functional/EntityTypeWithoutLanguageFormTest.php
@@ -19,7 +19,7 @@ class EntityTypeWithoutLanguageFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'language_test',
   ];
diff --git a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonAnonTest.php b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonAnonTest.php
index c548c17241..5036670a17 100644
--- a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonAnonTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ConfigurableLanguageHalJsonAnonTest extends ConfigurableLanguageResourceTe
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonBasicAuthTest.php b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonBasicAuthTest.php
index 3239b7e22c..334a3c8b9a 100644
--- a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ConfigurableLanguageHalJsonBasicAuthTest extends ConfigurableLanguageResou
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonCookieTest.php b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonCookieTest.php
index 9ad7561067..fbcb928cbb 100644
--- a/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonCookieTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ConfigurableLanguageHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ConfigurableLanguageHalJsonCookieTest extends ConfigurableLanguageResource
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonAnonTest.php b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonAnonTest.php
index d5b7947ed4..4047aaba8b 100644
--- a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonAnonTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ContentLanguageSettingsHalJsonAnonTest extends ContentLanguageSettingsReso
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonBasicAuthTest.php b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonBasicAuthTest.php
index 61306eaf5e..a761ed6407 100644
--- a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ContentLanguageSettingsHalJsonBasicAuthTest extends ContentLanguageSetting
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonCookieTest.php b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonCookieTest.php
index 63584f6489..6e65edc07c 100644
--- a/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonCookieTest.php
+++ b/core/modules/language/tests/src/Functional/Hal/ContentLanguageSettingsHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ContentLanguageSettingsHalJsonCookieTest extends ContentLanguageSettingsRe
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/LanguageBlockSettingsVisibilityTest.php b/core/modules/language/tests/src/Functional/LanguageBlockSettingsVisibilityTest.php
index 003c5a63fa..545640270b 100644
--- a/core/modules/language/tests/src/Functional/LanguageBlockSettingsVisibilityTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageBlockSettingsVisibilityTest.php
@@ -11,7 +11,7 @@
  */
 class LanguageBlockSettingsVisibilityTest extends BrowserTestBase {
 
-  public static $modules = ['block', 'language'];
+  protected static $modules = ['block', 'language'];
 
   public function testUnnecessaryLanguageSettingsVisibility() {
     $admin_user = $this->drupalCreateUser(['administer languages', 'access administration pages', 'administer blocks']);
diff --git a/core/modules/language/tests/src/Functional/LanguageBreadcrumbTest.php b/core/modules/language/tests/src/Functional/LanguageBreadcrumbTest.php
index e15fcf7a6d..7afa3653b7 100644
--- a/core/modules/language/tests/src/Functional/LanguageBreadcrumbTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageBreadcrumbTest.php
@@ -17,7 +17,7 @@ class LanguageBreadcrumbTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'block', 'filter'];
+  protected static $modules = ['language', 'block', 'filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/LanguageBrowserDetectionTest.php b/core/modules/language/tests/src/Functional/LanguageBrowserDetectionTest.php
index a63ff451f1..713f23ac4b 100644
--- a/core/modules/language/tests/src/Functional/LanguageBrowserDetectionTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageBrowserDetectionTest.php
@@ -11,7 +11,7 @@
  */
 class LanguageBrowserDetectionTest extends BrowserTestBase {
 
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests for adding, editing and deleting mappings between browser language
diff --git a/core/modules/language/tests/src/Functional/LanguageConfigOverrideImportTest.php b/core/modules/language/tests/src/Functional/LanguageConfigOverrideImportTest.php
index 2ddd4963ed..956ded16af 100644
--- a/core/modules/language/tests/src/Functional/LanguageConfigOverrideImportTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageConfigOverrideImportTest.php
@@ -17,7 +17,7 @@ class LanguageConfigOverrideImportTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'config', 'locale', 'config_translation'];
+  protected static $modules = ['language', 'config', 'locale', 'config_translation'];
 
   /**
    * Tests that language can be enabled and overrides are created during a sync.
diff --git a/core/modules/language/tests/src/Functional/LanguageConfigSchemaTest.php b/core/modules/language/tests/src/Functional/LanguageConfigSchemaTest.php
index e19fe53da3..b029b7f744 100644
--- a/core/modules/language/tests/src/Functional/LanguageConfigSchemaTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageConfigSchemaTest.php
@@ -19,7 +19,7 @@ class LanguageConfigSchemaTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'menu_link_content'];
+  protected static $modules = ['language', 'menu_link_content'];
 
   /**
    * A user with administrative permissions.
diff --git a/core/modules/language/tests/src/Functional/LanguageConfigurationElementTest.php b/core/modules/language/tests/src/Functional/LanguageConfigurationElementTest.php
index 0f3dd1f0ba..64f700b419 100644
--- a/core/modules/language/tests/src/Functional/LanguageConfigurationElementTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageConfigurationElementTest.php
@@ -20,7 +20,7 @@ class LanguageConfigurationElementTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'node', 'language', 'language_elements_test', 'field_ui'];
+  protected static $modules = ['taxonomy', 'node', 'language', 'language_elements_test', 'field_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Functional/LanguageConfigurationTest.php b/core/modules/language/tests/src/Functional/LanguageConfigurationTest.php
index 7095bc18e2..88fc25527e 100644
--- a/core/modules/language/tests/src/Functional/LanguageConfigurationTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageConfigurationTest.php
@@ -18,7 +18,7 @@ class LanguageConfigurationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Functional tests for adding, editing and deleting languages.
diff --git a/core/modules/language/tests/src/Functional/LanguageCustomLanguageConfigurationTest.php b/core/modules/language/tests/src/Functional/LanguageCustomLanguageConfigurationTest.php
index a0510beca7..152eb516ec 100644
--- a/core/modules/language/tests/src/Functional/LanguageCustomLanguageConfigurationTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageCustomLanguageConfigurationTest.php
@@ -18,7 +18,7 @@ class LanguageCustomLanguageConfigurationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Functional tests for adding, editing and deleting languages.
diff --git a/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php b/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
index 013d00d8db..b419e193c6 100644
--- a/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageListModuleInstallTest.php
@@ -17,7 +17,7 @@ class LanguageListModuleInstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language_test'];
+  protected static $modules = ['language_test'];
 
   /**
    * Tests enabling Language.
diff --git a/core/modules/language/tests/src/Functional/LanguageListTest.php b/core/modules/language/tests/src/Functional/LanguageListTest.php
index 8c671cfccf..0c6606e8af 100644
--- a/core/modules/language/tests/src/Functional/LanguageListTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageListTest.php
@@ -19,7 +19,7 @@ class LanguageListTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Functional tests for adding, editing and deleting languages.
diff --git a/core/modules/language/tests/src/Functional/LanguageLocaleListTest.php b/core/modules/language/tests/src/Functional/LanguageLocaleListTest.php
index a39a112424..4201ab570b 100644
--- a/core/modules/language/tests/src/Functional/LanguageLocaleListTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageLocaleListTest.php
@@ -16,7 +16,7 @@ class LanguageLocaleListTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'locale'];
+  protected static $modules = ['language', 'locale'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/LanguageNegotiationContentEntityTest.php b/core/modules/language/tests/src/Functional/LanguageNegotiationContentEntityTest.php
index 3ac9406252..c83204e6ce 100644
--- a/core/modules/language/tests/src/Functional/LanguageNegotiationContentEntityTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageNegotiationContentEntityTest.php
@@ -25,7 +25,7 @@ class LanguageNegotiationContentEntityTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'language_test', 'entity_test', 'system'];
+  protected static $modules = ['language', 'language_test', 'entity_test', 'system'];
 
   /**
    * The entity being used for testing.
diff --git a/core/modules/language/tests/src/Functional/LanguageNegotiationInfoTest.php b/core/modules/language/tests/src/Functional/LanguageNegotiationInfoTest.php
index c5e3c2c7b1..3ab2dcd334 100644
--- a/core/modules/language/tests/src/Functional/LanguageNegotiationInfoTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageNegotiationInfoTest.php
@@ -18,7 +18,7 @@ class LanguageNegotiationInfoTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation'];
+  protected static $modules = ['language', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/LanguageNegotiationUrlTest.php b/core/modules/language/tests/src/Functional/LanguageNegotiationUrlTest.php
index 07ae85d433..07f75216be 100644
--- a/core/modules/language/tests/src/Functional/LanguageNegotiationUrlTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageNegotiationUrlTest.php
@@ -16,7 +16,7 @@ class LanguageNegotiationUrlTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'node',
     'path',
diff --git a/core/modules/language/tests/src/Functional/LanguagePathMonolingualTest.php b/core/modules/language/tests/src/Functional/LanguagePathMonolingualTest.php
index 17ff3f936d..a5d663b12b 100644
--- a/core/modules/language/tests/src/Functional/LanguagePathMonolingualTest.php
+++ b/core/modules/language/tests/src/Functional/LanguagePathMonolingualTest.php
@@ -16,7 +16,7 @@ class LanguagePathMonolingualTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'language', 'path'];
+  protected static $modules = ['block', 'language', 'path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Functional/LanguageSelectorTranslatableTest.php b/core/modules/language/tests/src/Functional/LanguageSelectorTranslatableTest.php
index 9526d226fd..1b3531a2ef 100644
--- a/core/modules/language/tests/src/Functional/LanguageSelectorTranslatableTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageSelectorTranslatableTest.php
@@ -16,7 +16,7 @@ class LanguageSelectorTranslatableTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'node',
diff --git a/core/modules/language/tests/src/Functional/LanguageSwitchingTest.php b/core/modules/language/tests/src/Functional/LanguageSwitchingTest.php
index 1303082c15..0ec4fccccd 100644
--- a/core/modules/language/tests/src/Functional/LanguageSwitchingTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageSwitchingTest.php
@@ -20,7 +20,7 @@ class LanguageSwitchingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'locale_test', 'language', 'block', 'language_test', 'menu_ui'];
+  protected static $modules = ['locale', 'locale_test', 'language', 'block', 'language_test', 'menu_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Functional/LanguageTourTest.php b/core/modules/language/tests/src/Functional/LanguageTourTest.php
index 13b29f2ef5..c8cba54ea3 100644
--- a/core/modules/language/tests/src/Functional/LanguageTourTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageTourTest.php
@@ -23,7 +23,7 @@ class LanguageTourTest extends TourTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'language', 'tour'];
+  protected static $modules = ['block', 'language', 'tour'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/LanguageUILanguageNegotiationTest.php b/core/modules/language/tests/src/Functional/LanguageUILanguageNegotiationTest.php
index 34f0c81f01..49ae232dc0 100644
--- a/core/modules/language/tests/src/Functional/LanguageUILanguageNegotiationTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageUILanguageNegotiationTest.php
@@ -48,7 +48,7 @@ class LanguageUILanguageNegotiationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'language_test', 'block', 'user', 'content_translation'];
+  protected static $modules = ['locale', 'language_test', 'block', 'user', 'content_translation'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Functional/LanguageUrlRewritingTest.php b/core/modules/language/tests/src/Functional/LanguageUrlRewritingTest.php
index 07eec52514..22b38823f5 100644
--- a/core/modules/language/tests/src/Functional/LanguageUrlRewritingTest.php
+++ b/core/modules/language/tests/src/Functional/LanguageUrlRewritingTest.php
@@ -21,7 +21,7 @@ class LanguageUrlRewritingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'language_test'];
+  protected static $modules = ['language', 'language_test'];
 
   /**
    * An user with permissions to administer languages.
diff --git a/core/modules/language/tests/src/Functional/Migrate/MigrateLanguageTest.php b/core/modules/language/tests/src/Functional/Migrate/MigrateLanguageTest.php
index 9a2702da2b..ef9b0216e4 100644
--- a/core/modules/language/tests/src/Functional/Migrate/MigrateLanguageTest.php
+++ b/core/modules/language/tests/src/Functional/Migrate/MigrateLanguageTest.php
@@ -14,7 +14,7 @@ class MigrateLanguageTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Asserts various properties of a configurable language entity.
diff --git a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php
index 847e781640..804e6e1633 100644
--- a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ConfigurableLanguageJsonBasicAuthTest extends ConfigurableLanguageResource
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageResourceTestBase.php b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageResourceTestBase.php
index a0dd460541..cdd2e4b1c9 100644
--- a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageResourceTestBase.php
+++ b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageResourceTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageXmlBasicAuthTest.php b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageXmlBasicAuthTest.php
index 7a79c4d433..7e3edb1da1 100644
--- a/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageXmlBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ConfigurableLanguageXmlBasicAuthTest extends ConfigurableLanguageResourceT
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsJsonBasicAuthTest.php b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsJsonBasicAuthTest.php
index 14437a9092..b15760d106 100644
--- a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsJsonBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ContentLanguageSettingsJsonBasicAuthTest extends ContentLanguageSettingsRe
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsResourceTestBase.php b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsResourceTestBase.php
index 6283484368..79425367cd 100644
--- a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsResourceTestBase.php
+++ b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'node'];
+  protected static $modules = ['language', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsXmlBasicAuthTest.php b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsXmlBasicAuthTest.php
index 741e75bcd3..9252312dd5 100644
--- a/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsXmlBasicAuthTest.php
+++ b/core/modules/language/tests/src/Functional/Rest/ContentLanguageSettingsXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ContentLanguageSettingsXmlBasicAuthTest extends ContentLanguageSettingsRes
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
index af7eed4b7f..f5390562f7 100644
--- a/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
+++ b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
@@ -32,7 +32,7 @@ class LanguageConditionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'language'];
+  protected static $modules = ['system', 'language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/language/tests/src/Kernel/ConfigurableLanguageManagerTest.php b/core/modules/language/tests/src/Kernel/ConfigurableLanguageManagerTest.php
index 92ab889ce8..fecdfa4a5f 100644
--- a/core/modules/language/tests/src/Kernel/ConfigurableLanguageManagerTest.php
+++ b/core/modules/language/tests/src/Kernel/ConfigurableLanguageManagerTest.php
@@ -16,7 +16,7 @@ class ConfigurableLanguageManagerTest extends LanguageTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * The language negotiator.
diff --git a/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php b/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
index 00af14cbd3..1a717ddeb7 100644
--- a/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/ConfigurableLanguageTest.php
@@ -18,7 +18,7 @@ class ConfigurableLanguageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests configurable language name methods.
diff --git a/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php b/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
index 88abdd9006..97a9616f0f 100644
--- a/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/EntityDefaultLanguageTest.php
@@ -18,7 +18,7 @@ class EntityDefaultLanguageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node', 'field', 'text', 'user', 'system'];
+  protected static $modules = ['language', 'node', 'field', 'text', 'user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php b/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
index 8154e42a46..dcdf910979 100644
--- a/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/EntityUrlLanguageTest.php
@@ -22,7 +22,7 @@ class EntityUrlLanguageTest extends LanguageTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'user'];
+  protected static $modules = ['entity_test', 'user'];
 
   /**
    * The entity being used for testing.
diff --git a/core/modules/language/tests/src/Kernel/LanguageConfigFactoryOverrideTest.php b/core/modules/language/tests/src/Kernel/LanguageConfigFactoryOverrideTest.php
index 3082697b04..722fcbc8ad 100644
--- a/core/modules/language/tests/src/Kernel/LanguageConfigFactoryOverrideTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageConfigFactoryOverrideTest.php
@@ -17,7 +17,7 @@ class LanguageConfigFactoryOverrideTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'language'];
+  protected static $modules = ['system', 'language'];
 
   /**
    * Tests language.config_factory_override service has the default language.
diff --git a/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php b/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
index 7d505baf78..2b12b54945 100644
--- a/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
+++ b/core/modules/language/tests/src/Kernel/LanguageConfigOverrideInstallTest.php
@@ -17,7 +17,7 @@ class LanguageConfigOverrideInstallTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'config_events_test'];
+  protected static $modules = ['language', 'config_events_test'];
 
   /**
    * Tests the configuration events are not fired during install of overrides.
diff --git a/core/modules/language/tests/src/Kernel/LanguageTestBase.php b/core/modules/language/tests/src/Kernel/LanguageTestBase.php
index f4dcbd2f9d..458eeaec53 100644
--- a/core/modules/language/tests/src/Kernel/LanguageTestBase.php
+++ b/core/modules/language/tests/src/Kernel/LanguageTestBase.php
@@ -9,7 +9,7 @@
  */
 abstract class LanguageTestBase extends KernelTestBase {
 
-  public static $modules = ['system', 'language', 'language_test'];
+  protected static $modules = ['system', 'language', 'language_test'];
   /**
    * The language manager.
    *
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateDefaultLanguageTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateDefaultLanguageTest.php
index e76b4553ee..73aeac4350 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateDefaultLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateDefaultLanguageTest.php
@@ -16,7 +16,7 @@ class MigrateDefaultLanguageTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests language_default migration with an existing language.
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentMenuSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentMenuSettingsTest.php
index 0148452dc9..e2a09c0d69 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentMenuSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentMenuSettingsTest.php
@@ -17,7 +17,7 @@ class MigrateLanguageContentMenuSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'menu_link_content',
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
index 546ab25e03..82e6ba8ce8 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
@@ -16,7 +16,7 @@ class MigrateLanguageContentSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'text', 'language', 'content_translation', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'language', 'content_translation', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
index 96bc4a0d8c..1ad87bda7b 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageNegotiationSettingsTest.php
@@ -15,7 +15,7 @@ class MigrateLanguageNegotiationSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests the migration with LANGUAGE_NEGOTIATION_PATH_DEFAULT.
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateDefaultLanguageTest.php b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateDefaultLanguageTest.php
index 2a11b25628..61f9249167 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateDefaultLanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateDefaultLanguageTest.php
@@ -16,7 +16,7 @@ class MigrateDefaultLanguageTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests language_default migration with a non-existing language.
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
index e584467c92..ddd7f35ed7 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageContentSettingsTest.php
@@ -16,7 +16,7 @@ class MigrateLanguageContentSettingsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'text', 'language', 'content_translation', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'language', 'content_translation', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageNegotiationSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageNegotiationSettingsTest.php
index cd1a21835e..875135e2bb 100644
--- a/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageNegotiationSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Migrate/d7/MigrateLanguageNegotiationSettingsTest.php
@@ -15,7 +15,7 @@ class MigrateLanguageNegotiationSettingsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Tests migration of language types variables to language.types.yml.
diff --git a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/LanguageTest.php b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/LanguageTest.php
index 6aa318eb41..d04b57af5b 100644
--- a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/LanguageTest.php
+++ b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/LanguageTest.php
@@ -15,7 +15,7 @@ class LanguageTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'migrate_drupal'];
+  protected static $modules = ['language', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d6/LanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d6/LanguageContentSettingsTest.php
index a4c7534e5f..f4fa2dacce 100644
--- a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d6/LanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d6/LanguageContentSettingsTest.php
@@ -16,7 +16,7 @@ class LanguageContentSettingsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'migrate_drupal'];
+  protected static $modules = ['language', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d7/LanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d7/LanguageContentSettingsTest.php
index 39d6450817..3fc1df57c3 100644
--- a/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d7/LanguageContentSettingsTest.php
+++ b/core/modules/language/tests/src/Kernel/Plugin/migrate/source/d7/LanguageContentSettingsTest.php
@@ -16,7 +16,7 @@ class LanguageContentSettingsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'migrate_drupal'];
+  protected static $modules = ['language', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/language/tests/src/Kernel/Views/LanguageTestBase.php b/core/modules/language/tests/src/Kernel/Views/LanguageTestBase.php
index cab6fc84e0..fc4cabf1ba 100644
--- a/core/modules/language/tests/src/Kernel/Views/LanguageTestBase.php
+++ b/core/modules/language/tests/src/Kernel/Views/LanguageTestBase.php
@@ -15,7 +15,7 @@
    *
    * @var array
    */
-  public static $modules = ['system', 'language'];
+  protected static $modules = ['system', 'language'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp();
diff --git a/core/modules/layout_builder/tests/src/Functional/LayoutBuilderTest.php b/core/modules/layout_builder/tests/src/Functional/LayoutBuilderTest.php
index 293f7b9f7c..0fbc5f8b22 100644
--- a/core/modules/layout_builder/tests/src/Functional/LayoutBuilderTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/LayoutBuilderTest.php
@@ -16,7 +16,7 @@ class LayoutBuilderTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'views',
     'layout_builder',
     'layout_builder_views_test',
diff --git a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
index e4af3290c4..6fde76abc2 100644
--- a/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
+++ b/core/modules/layout_builder/tests/src/Functional/LayoutSectionTest.php
@@ -18,7 +18,7 @@ class LayoutSectionTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_ui', 'layout_builder', 'node', 'block_test'];
+  protected static $modules = ['field_ui', 'layout_builder', 'node', 'block_test'];
 
   /**
    * The name of the layout section field.
diff --git a/core/modules/layout_builder/tests/src/FunctionalJavascript/AjaxBlockTest.php b/core/modules/layout_builder/tests/src/FunctionalJavascript/AjaxBlockTest.php
index 653185fe89..256a3177e7 100644
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/AjaxBlockTest.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/AjaxBlockTest.php
@@ -14,7 +14,7 @@ class AjaxBlockTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'node',
     'datetime',
diff --git a/core/modules/layout_builder/tests/src/FunctionalJavascript/FieldBlockTest.php b/core/modules/layout_builder/tests/src/FunctionalJavascript/FieldBlockTest.php
index f2ecd52b3b..a4db0f1ef6 100644
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/FieldBlockTest.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/FieldBlockTest.php
@@ -16,7 +16,7 @@ class FieldBlockTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'datetime', 'layout_builder', 'user'];
+  protected static $modules = ['block', 'datetime', 'layout_builder', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockPrivateFilesTest.php b/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockPrivateFilesTest.php
index 05892bd314..2733dccd55 100644
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockPrivateFilesTest.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockPrivateFilesTest.php
@@ -22,7 +22,7 @@ class InlineBlockPrivateFilesTest extends InlineBlockTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'file',
   ];
 
diff --git a/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTestBase.php b/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTestBase.php
index 6c99c6c39f..a7adab122b 100644
--- a/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTestBase.php
+++ b/core/modules/layout_builder/tests/src/FunctionalJavascript/InlineBlockTestBase.php
@@ -26,7 +26,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block_content',
     'layout_builder',
     'block',
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
index 72ee01ac60..4113bb258a 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderCompatibilityTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'layout_discovery',
   ];
 
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderFieldLayoutCompatibilityTest.php b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderFieldLayoutCompatibilityTest.php
index 57dacb5b18..943a4bfd86 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderFieldLayoutCompatibilityTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutBuilderFieldLayoutCompatibilityTest.php
@@ -14,7 +14,7 @@ class LayoutBuilderFieldLayoutCompatibilityTest extends LayoutBuilderCompatibili
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'field_layout',
   ];
 
diff --git a/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemListTest.php b/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemListTest.php
index 5bd354675c..30ffe6961e 100644
--- a/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemListTest.php
+++ b/core/modules/layout_builder/tests/src/Kernel/LayoutSectionItemListTest.php
@@ -17,7 +17,7 @@ class LayoutSectionItemListTest extends SectionStorageTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'field',
     'text',
   ];
diff --git a/core/modules/layout_builder/tests/src/Kernel/SectionStorageTestBase.php b/core/modules/layout_builder/tests/src/Kernel/SectionStorageTestBase.php
index 1879977633..1abad5f9c0 100644
--- a/core/modules/layout_builder/tests/src/Kernel/SectionStorageTestBase.php
+++ b/core/modules/layout_builder/tests/src/Kernel/SectionStorageTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'layout_builder',
     'layout_discovery',
     'layout_test',
diff --git a/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php b/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
index c7be49ba2b..81c011a85e 100644
--- a/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
+++ b/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
@@ -15,7 +15,7 @@ class LayoutTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'layout_discovery', 'layout_test'];
+  protected static $modules = ['system', 'layout_discovery', 'layout_test'];
 
   /**
    * The layout plugin manager.
diff --git a/core/modules/link/src/Tests/Views/LinkViewsTokensTest.php b/core/modules/link/src/Tests/Views/LinkViewsTokensTest.php
index f3ff80a1bc..1d10b79af8 100644
--- a/core/modules/link/src/Tests/Views/LinkViewsTokensTest.php
+++ b/core/modules/link/src/Tests/Views/LinkViewsTokensTest.php
@@ -19,7 +19,7 @@ class LinkViewsTokensTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['link_test_views'];
+  protected static $modules = ['link_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/link/tests/src/Functional/LinkFieldTest.php b/core/modules/link/tests/src/Functional/LinkFieldTest.php
index 4df94dd6cf..8e9cdf23c4 100644
--- a/core/modules/link/tests/src/Functional/LinkFieldTest.php
+++ b/core/modules/link/tests/src/Functional/LinkFieldTest.php
@@ -24,7 +24,7 @@ class LinkFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'link',
     'node',
diff --git a/core/modules/link/tests/src/Functional/LinkFieldUITest.php b/core/modules/link/tests/src/Functional/LinkFieldUITest.php
index bd2433f903..92aed61f93 100644
--- a/core/modules/link/tests/src/Functional/LinkFieldUITest.php
+++ b/core/modules/link/tests/src/Functional/LinkFieldUITest.php
@@ -24,7 +24,7 @@ class LinkFieldUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'link', 'field_ui', 'block'];
+  protected static $modules = ['node', 'link', 'field_ui', 'block'];
 
   /**
    * A user that can edit content types.
diff --git a/core/modules/link/tests/src/Kernel/LinkItemSerializationTest.php b/core/modules/link/tests/src/Kernel/LinkItemSerializationTest.php
index dde7dc117f..ae0cbf4f3a 100644
--- a/core/modules/link/tests/src/Kernel/LinkItemSerializationTest.php
+++ b/core/modules/link/tests/src/Kernel/LinkItemSerializationTest.php
@@ -19,7 +19,7 @@ class LinkItemSerializationTest extends FieldKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['link', 'serialization'];
+  protected static $modules = ['link', 'serialization'];
 
   /**
    * The serializer service.
diff --git a/core/modules/link/tests/src/Kernel/LinkItemTest.php b/core/modules/link/tests/src/Kernel/LinkItemTest.php
index ff4f840567..51a6cc3d05 100644
--- a/core/modules/link/tests/src/Kernel/LinkItemTest.php
+++ b/core/modules/link/tests/src/Kernel/LinkItemTest.php
@@ -24,7 +24,7 @@ class LinkItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['link'];
+  protected static $modules = ['link'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
index 058d9ddf8e..0239cdbd35 100644
--- a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
@@ -18,7 +18,7 @@ class LocaleConfigTranslationImportTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'locale_test_translate'];
+  protected static $modules = ['language', 'locale_test_translate'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
index 3d6c95084a..435d8881e2 100644
--- a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
@@ -24,7 +24,7 @@ class LocaleConfigTranslationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'contact', 'contact_test'];
+  protected static $modules = ['locale', 'contact', 'contact_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleContentTest.php b/core/modules/locale/tests/src/Functional/LocaleContentTest.php
index e7955503a4..51305bd9e1 100644
--- a/core/modules/locale/tests/src/Functional/LocaleContentTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleContentTest.php
@@ -19,7 +19,7 @@ class LocaleContentTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'locale'];
+  protected static $modules = ['node', 'locale'];
 
   /**
    * Verifies that machine name fields are always LTR.
diff --git a/core/modules/locale/tests/src/Functional/LocaleExportTest.php b/core/modules/locale/tests/src/Functional/LocaleExportTest.php
index 05621f6c13..4df30eb1c4 100644
--- a/core/modules/locale/tests/src/Functional/LocaleExportTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleExportTest.php
@@ -16,7 +16,7 @@ class LocaleExportTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   /**
    * A user able to create languages and export translations.
diff --git a/core/modules/locale/tests/src/Functional/LocaleFileSystemFormTest.php b/core/modules/locale/tests/src/Functional/LocaleFileSystemFormTest.php
index c38da43d77..c0f712c18d 100644
--- a/core/modules/locale/tests/src/Functional/LocaleFileSystemFormTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleFileSystemFormTest.php
@@ -16,7 +16,7 @@ class LocaleFileSystemFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleImportFunctionalTest.php b/core/modules/locale/tests/src/Functional/LocaleImportFunctionalTest.php
index c63c4e4261..ae787b8cd7 100644
--- a/core/modules/locale/tests/src/Functional/LocaleImportFunctionalTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleImportFunctionalTest.php
@@ -17,7 +17,7 @@ class LocaleImportFunctionalTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'dblog'];
+  protected static $modules = ['locale', 'dblog'];
 
   /**
    * A user able to create languages and import translations.
diff --git a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
index 1d6fde703b..8cba55612c 100644
--- a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
@@ -18,7 +18,7 @@ class LocaleJavascriptTranslationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'locale_test'];
+  protected static $modules = ['locale', 'locale_test'];
 
   public function testFileParsing() {
 
diff --git a/core/modules/locale/tests/src/Functional/LocaleLibraryAlterTest.php b/core/modules/locale/tests/src/Functional/LocaleLibraryAlterTest.php
index 5425fc5f4c..f18ec5d976 100644
--- a/core/modules/locale/tests/src/Functional/LocaleLibraryAlterTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleLibraryAlterTest.php
@@ -19,7 +19,7 @@ class LocaleLibraryAlterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   /**
    * Verifies that the datepicker can be localized.
diff --git a/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php b/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php
index 4afd1c81ff..97cdc22785 100644
--- a/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php
@@ -18,7 +18,7 @@ class LocaleLocaleLookupTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'locale_test'];
+  protected static $modules = ['locale', 'locale_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocalePathTest.php b/core/modules/locale/tests/src/Functional/LocalePathTest.php
index 16cc26865e..041f7b0c7a 100644
--- a/core/modules/locale/tests/src/Functional/LocalePathTest.php
+++ b/core/modules/locale/tests/src/Functional/LocalePathTest.php
@@ -18,7 +18,7 @@ class LocalePathTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'locale', 'path', 'views'];
+  protected static $modules = ['node', 'locale', 'path', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocalePluralFormatTest.php b/core/modules/locale/tests/src/Functional/LocalePluralFormatTest.php
index 57916caf04..51bb5aa68f 100644
--- a/core/modules/locale/tests/src/Functional/LocalePluralFormatTest.php
+++ b/core/modules/locale/tests/src/Functional/LocalePluralFormatTest.php
@@ -24,7 +24,7 @@ class LocalePluralFormatTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleStringTest.php b/core/modules/locale/tests/src/Functional/LocaleStringTest.php
index 601b7388e6..0f662cd9c5 100644
--- a/core/modules/locale/tests/src/Functional/LocaleStringTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleStringTest.php
@@ -17,7 +17,7 @@ class LocaleStringTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   /**
    * The locale storage.
diff --git a/core/modules/locale/tests/src/Functional/LocaleTranslateStringTourTest.php b/core/modules/locale/tests/src/Functional/LocaleTranslateStringTourTest.php
index ffd5bc7b02..e288053a48 100644
--- a/core/modules/locale/tests/src/Functional/LocaleTranslateStringTourTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleTranslateStringTourTest.php
@@ -23,7 +23,7 @@ class LocaleTranslateStringTourTest extends TourTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'tour'];
+  protected static $modules = ['locale', 'tour'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleTranslatedSchemaDefinitionTest.php b/core/modules/locale/tests/src/Functional/LocaleTranslatedSchemaDefinitionTest.php
index 39d7c3d533..2f5e48f831 100644
--- a/core/modules/locale/tests/src/Functional/LocaleTranslatedSchemaDefinitionTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleTranslatedSchemaDefinitionTest.php
@@ -17,7 +17,7 @@ class LocaleTranslatedSchemaDefinitionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'locale', 'node'];
+  protected static $modules = ['language', 'locale', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
index a51eb876e5..5315e3d6a9 100644
--- a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
@@ -20,7 +20,7 @@ class LocaleTranslationUiTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   /**
    * Enable interface translation to English.
diff --git a/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
index 1a5debf44a..a63e25a50a 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
@@ -45,7 +45,7 @@
    *
    * @var array
    */
-  public static $modules = ['locale', 'locale_test'];
+  protected static $modules = ['locale', 'locale_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Functional/LocaleUpdateDevelopmentReleaseTest.php b/core/modules/locale/tests/src/Functional/LocaleUpdateDevelopmentReleaseTest.php
index 5c972d1ef3..00b86a35e5 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateDevelopmentReleaseTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateDevelopmentReleaseTest.php
@@ -11,7 +11,7 @@
  */
 class LocaleUpdateDevelopmentReleaseTest extends BrowserTestBase {
 
-  public static $modules = ['locale', 'locale_test_development_release'];
+  protected static $modules = ['locale', 'locale_test_development_release'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php b/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php
index 0ab558503c..f95044c986 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php
@@ -16,7 +16,7 @@ class LocaleUpdateInterfaceTest extends LocaleUpdateBase {
    *
    * @var array
    */
-  public static $modules = ['locale_test_translate'];
+  protected static $modules = ['locale_test_translate'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
index 8389b6e973..55e656e53c 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigManagerTest.php
@@ -18,7 +18,7 @@ class LocaleConfigManagerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'language', 'locale', 'locale_test', 'block'];
+  protected static $modules = ['system', 'language', 'locale', 'locale_test', 'block'];
 
   /**
    * This test creates simple config on the fly breaking schema checking.
diff --git a/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
index 128b7b1d30..10e05d0195 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigSubscriberTest.php
@@ -18,7 +18,7 @@ class LocaleConfigSubscriberTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'locale', 'system', 'locale_test'];
+  protected static $modules = ['language', 'locale', 'system', 'locale_test'];
 
   /**
    * The configurable language manager used in this test.
diff --git a/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php b/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
index 07909bacc4..0b25752854 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleConfigurableLanguageManagerTest.php
@@ -18,7 +18,7 @@ class LocaleConfigurableLanguageManagerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'locale'];
+  protected static $modules = ['language', 'locale'];
 
   public function testGetLanguages() {
     $this->installSchema('locale', ['locales_source', 'locales_target', 'locales_location']);
diff --git a/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php b/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php
index b98bc0552a..98101dae91 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleDeprecationsTest.php
@@ -17,7 +17,7 @@ class LocaleDeprecationsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'system'];
+  protected static $modules = ['locale', 'system'];
 
   /**
    * @expectedDeprecation locale_translation_manual_status() is deprecated in Drupal 8.5.0 and will be removed before Drupal 9.0.0. It is unused by Drupal core. Duplicate this function in your own extension if you need its behavior.
diff --git a/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php b/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
index 4129cdc883..5cc4cde577 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
@@ -16,7 +16,7 @@ class LocaleStringIsSafeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale', 'locale_test'];
+  protected static $modules = ['locale', 'locale_test'];
 
   /**
    * Tests for locale_string_is_safe().
diff --git a/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php b/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
index 8b9b7974dc..38f04a58df 100644
--- a/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
+++ b/core/modules/locale/tests/src/Kernel/LocaleTranslationProjectsTest.php
@@ -14,7 +14,7 @@ class LocaleTranslationProjectsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['locale', 'locale_test', 'system'];
+  protected static $modules = ['locale', 'locale_test', 'system'];
 
   /**
    * The module handler used in this test.
diff --git a/core/modules/locale/tests/src/Kernel/Migrate/MigrateLocaleConfigsTest.php b/core/modules/locale/tests/src/Kernel/Migrate/MigrateLocaleConfigsTest.php
index b4449184a3..4327fe3363 100644
--- a/core/modules/locale/tests/src/Kernel/Migrate/MigrateLocaleConfigsTest.php
+++ b/core/modules/locale/tests/src/Kernel/Migrate/MigrateLocaleConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateLocaleConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['locale', 'language'];
+  protected static $modules = ['locale', 'language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/FieldFormatter/OEmbedFormatterTest.php b/core/modules/media/tests/src/Functional/FieldFormatter/OEmbedFormatterTest.php
index 2d344bdd20..9e15f4649d 100644
--- a/core/modules/media/tests/src/Functional/FieldFormatter/OEmbedFormatterTest.php
+++ b/core/modules/media/tests/src/Functional/FieldFormatter/OEmbedFormatterTest.php
@@ -21,7 +21,7 @@ class OEmbedFormatterTest extends MediaFunctionalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'field_ui',
     'link',
     'media_test_oembed',
diff --git a/core/modules/media/tests/src/Functional/Hal/MediaHalJsonAnonTest.php b/core/modules/media/tests/src/Functional/Hal/MediaHalJsonAnonTest.php
index 5b8de2dacb..957eca3705 100644
--- a/core/modules/media/tests/src/Functional/Hal/MediaHalJsonAnonTest.php
+++ b/core/modules/media/tests/src/Functional/Hal/MediaHalJsonAnonTest.php
@@ -20,7 +20,7 @@ class MediaHalJsonAnonTest extends MediaResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Hal/MediaHalJsonBasicAuthTest.php b/core/modules/media/tests/src/Functional/Hal/MediaHalJsonBasicAuthTest.php
index 73d37b377e..89e4a4704d 100644
--- a/core/modules/media/tests/src/Functional/Hal/MediaHalJsonBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Hal/MediaHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MediaHalJsonBasicAuthTest extends MediaHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonAnonTest.php b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonAnonTest.php
index 6a5611f9c7..52a5822740 100644
--- a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonAnonTest.php
+++ b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class MediaTypeHalJsonAnonTest extends MediaTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonBasicAuthTest.php b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonBasicAuthTest.php
index 0ef13e9952..f69022efa8 100644
--- a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class MediaTypeHalJsonBasicAuthTest extends MediaTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonCookieTest.php b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonCookieTest.php
index c66b499ef5..1e9fc38c13 100644
--- a/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonCookieTest.php
+++ b/core/modules/media/tests/src/Functional/Hal/MediaTypeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class MediaTypeHalJsonCookieTest extends MediaTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/MediaAccessTest.php b/core/modules/media/tests/src/Functional/MediaAccessTest.php
index 4672c3e288..d97487cf71 100644
--- a/core/modules/media/tests/src/Functional/MediaAccessTest.php
+++ b/core/modules/media/tests/src/Functional/MediaAccessTest.php
@@ -19,7 +19,7 @@ class MediaAccessTest extends MediaFunctionalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/Functional/MediaBulkFormTest.php b/core/modules/media/tests/src/Functional/MediaBulkFormTest.php
index fb9caf1fdd..51359b5f7b 100644
--- a/core/modules/media/tests/src/Functional/MediaBulkFormTest.php
+++ b/core/modules/media/tests/src/Functional/MediaBulkFormTest.php
@@ -17,7 +17,7 @@ class MediaBulkFormTest extends MediaFunctionalTestBase {
    *
    * @var array
    */
-  public static $modules = ['media_test_views'];
+  protected static $modules = ['media_test_views'];
 
   /**
    * The test media type.
diff --git a/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php b/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
index 4cacf3d467..161da2e686 100644
--- a/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
+++ b/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
@@ -19,7 +19,7 @@ class MediaCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'media',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/Functional/MediaContextualLinksTest.php b/core/modules/media/tests/src/Functional/MediaContextualLinksTest.php
index 540afac6a2..9977bd9ef0 100644
--- a/core/modules/media/tests/src/Functional/MediaContextualLinksTest.php
+++ b/core/modules/media/tests/src/Functional/MediaContextualLinksTest.php
@@ -14,7 +14,7 @@ class MediaContextualLinksTest extends MediaFunctionalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
   ];
 
diff --git a/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php b/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
index b786d2e3a1..2465695ff3 100644
--- a/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
+++ b/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'node',
     'field_ui',
diff --git a/core/modules/media/tests/src/Functional/MediaInstallTest.php b/core/modules/media/tests/src/Functional/MediaInstallTest.php
index 010f07698a..77ea8a96df 100644
--- a/core/modules/media/tests/src/Functional/MediaInstallTest.php
+++ b/core/modules/media/tests/src/Functional/MediaInstallTest.php
@@ -14,7 +14,7 @@ class MediaInstallTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/MediaTemplateSuggestionsTest.php b/core/modules/media/tests/src/Functional/MediaTemplateSuggestionsTest.php
index 916eb7cfc2..dac5f51611 100644
--- a/core/modules/media/tests/src/Functional/MediaTemplateSuggestionsTest.php
+++ b/core/modules/media/tests/src/Functional/MediaTemplateSuggestionsTest.php
@@ -16,7 +16,7 @@ class MediaTemplateSuggestionsTest extends MediaFunctionalTestBase {
    *
    * @var array
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * Tests template suggestions from media_theme_suggestions_media().
diff --git a/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php b/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php
index fe39fd828e..70719527d5 100644
--- a/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php
+++ b/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php
@@ -21,7 +21,7 @@ class MediaUiFunctionalTest extends MediaFunctionalTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaJsonBasicAuthTest.php b/core/modules/media/tests/src/Functional/Rest/MediaJsonBasicAuthTest.php
index b124487d42..a201a3b471 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaJsonBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MediaJsonBasicAuthTest extends MediaResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
index 85e4e5d731..1f8446918c 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaResourceTestBase.php
@@ -22,7 +22,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaTypeJsonBasicAuthTest.php b/core/modules/media/tests/src/Functional/Rest/MediaTypeJsonBasicAuthTest.php
index 84b1a01c87..c264f94719 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaTypeJsonBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaTypeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MediaTypeJsonBasicAuthTest extends MediaTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaTypeResourceTestBase.php b/core/modules/media/tests/src/Functional/Rest/MediaTypeResourceTestBase.php
index a11f8ef54d..7e3fb09069 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaTypeResourceTestBase.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaTypeResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaTypeXmlBasicAuthTest.php b/core/modules/media/tests/src/Functional/Rest/MediaTypeXmlBasicAuthTest.php
index 95de21197d..e8eac062c3 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaTypeXmlBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaTypeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class MediaTypeXmlBasicAuthTest extends MediaTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/Functional/Rest/MediaXmlBasicAuthTest.php b/core/modules/media/tests/src/Functional/Rest/MediaXmlBasicAuthTest.php
index 971e75f42c..64f9523bec 100644
--- a/core/modules/media/tests/src/Functional/Rest/MediaXmlBasicAuthTest.php
+++ b/core/modules/media/tests/src/Functional/Rest/MediaXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class MediaXmlBasicAuthTest extends MediaResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php b/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php
index 390e22075a..88fc891ef6 100644
--- a/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'node',
     'field_ui',
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceOEmbedVideoTest.php b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceOEmbedVideoTest.php
index cb7ae2ac5c..b95ac3ca1f 100644
--- a/core/modules/media/tests/src/FunctionalJavascript/MediaSourceOEmbedVideoTest.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/MediaSourceOEmbedVideoTest.php
@@ -19,7 +19,7 @@ class MediaSourceOEmbedVideoTest extends MediaSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media_test_oembed'];
+  protected static $modules = ['media_test_oembed'];
 
   use OEmbedTestTrait;
 
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaUiJavascriptTest.php b/core/modules/media/tests/src/FunctionalJavascript/MediaUiJavascriptTest.php
index a00a3c2010..e5af67b3a9 100644
--- a/core/modules/media/tests/src/FunctionalJavascript/MediaUiJavascriptTest.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/MediaUiJavascriptTest.php
@@ -19,7 +19,7 @@ class MediaUiJavascriptTest extends MediaJavascriptTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php b/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
index 1c6a879eea..164f12608f 100644
--- a/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
+++ b/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'media',
     'media_test_source',
     'image',
diff --git a/core/modules/media/tests/src/Kernel/MediaTranslationTest.php b/core/modules/media/tests/src/Kernel/MediaTranslationTest.php
index 50f8a7b9d5..dbd1e9f3e6 100644
--- a/core/modules/media/tests/src/Kernel/MediaTranslationTest.php
+++ b/core/modules/media/tests/src/Kernel/MediaTranslationTest.php
@@ -17,7 +17,7 @@ class MediaTranslationTest extends MediaKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * The test media translation type.
diff --git a/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonAnonTest.php b/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonAnonTest.php
index d374d2b5a1..29815bcb9a 100644
--- a/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonAnonTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class MenuLinkContentHalJsonAnonTest extends MenuLinkContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonBasicAuthTest.php b/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonBasicAuthTest.php
index 40e93a0c7b..dd24c9b7d6 100644
--- a/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonBasicAuthTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/Hal/MenuLinkContentHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MenuLinkContentHalJsonBasicAuthTest extends MenuLinkContentHalJsonAnonTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Functional/LinksTest.php b/core/modules/menu_link_content/tests/src/Functional/LinksTest.php
index 4d5bf9aa07..c37e959136 100644
--- a/core/modules/menu_link_content/tests/src/Functional/LinksTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/LinksTest.php
@@ -21,7 +21,7 @@ class LinksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test', 'menu_link_content'];
+  protected static $modules = ['router_test', 'menu_link_content'];
 
   /**
    * The menu link plugin manager.
diff --git a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentDeleteFormTest.php b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentDeleteFormTest.php
index cb1e10daf9..f5a8ba605d 100644
--- a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentDeleteFormTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentDeleteFormTest.php
@@ -18,7 +18,7 @@ class MenuLinkContentDeleteFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_link_content'];
+  protected static $modules = ['menu_link_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentFormTest.php b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentFormTest.php
index 8796bc7488..8eb99406f4 100644
--- a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentFormTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentFormTest.php
@@ -17,7 +17,7 @@ class MenuLinkContentFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_link_content',
   ];
 
diff --git a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentTranslationUITest.php b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentTranslationUITest.php
index 9fd1ce43fe..39cab40796 100644
--- a/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentTranslationUITest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/MenuLinkContentTranslationUITest.php
@@ -22,7 +22,7 @@ class MenuLinkContentTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'menu_link_content',
diff --git a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentJsonBasicAuthTest.php b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentJsonBasicAuthTest.php
index 269e94991e..5c6723167e 100644
--- a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentJsonBasicAuthTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MenuLinkContentJsonBasicAuthTest extends MenuLinkContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentResourceTestBase.php b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentResourceTestBase.php
index 9b03899e45..e77a74f230 100644
--- a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentResourceTestBase.php
+++ b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content'];
+  protected static $modules = ['menu_link_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentXmlBasicAuthTest.php b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentXmlBasicAuthTest.php
index 7bbf966170..4bb68bde39 100644
--- a/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentXmlBasicAuthTest.php
+++ b/core/modules/menu_link_content/tests/src/Functional/Rest/MenuLinkContentXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class MenuLinkContentXmlBasicAuthTest extends MenuLinkContentResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
index 118470fa12..5ec49d61a4 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
@@ -24,7 +24,7 @@ class MenuLinkContentCacheabilityBubblingTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'system', 'link', 'outbound_processing_test', 'url_alter_test', 'user'];
+  protected static $modules = ['menu_link_content', 'system', 'link', 'outbound_processing_test', 'url_alter_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeleteTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeleteTest.php
index 98dead915c..b5a3a1f97b 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeleteTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeleteTest.php
@@ -15,7 +15,7 @@ class MenuLinkContentDeleteTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'link', 'system'];
+  protected static $modules = ['menu_link_content', 'link', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
index 12d8d35afd..cbb0ba32f9 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
@@ -18,7 +18,7 @@ class MenuLinkContentDeriverTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'link', 'system', 'menu_link_content_dynamic_route'];
+  protected static $modules = ['menu_link_content', 'link', 'system', 'menu_link_content_dynamic_route'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Migrate/MigrateMenuLinkContentStubTest.php b/core/modules/menu_link_content/tests/src/Kernel/Migrate/MigrateMenuLinkContentStubTest.php
index 2c348cf554..2cad18980a 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Migrate/MigrateMenuLinkContentStubTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Migrate/MigrateMenuLinkContentStubTest.php
@@ -17,7 +17,7 @@ class MigrateMenuLinkContentStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'link'];
+  protected static $modules = ['menu_link_content', 'link'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTest.php b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTest.php
index 8fab083230..8433b4fcd6 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTest.php
@@ -16,7 +16,7 @@ class MigrateMenuLinkTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_link_content',
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTranslationTest.php b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTranslationTest.php
index d9b47b0592..af3a944e02 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTranslationTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d6/MigrateMenuLinkTranslationTest.php
@@ -15,7 +15,7 @@ class MigrateMenuLinkTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_ui',
     'menu_link_content',
     'language',
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d7/MigrateMenuLinkTest.php b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d7/MigrateMenuLinkTest.php
index e9913f6fa6..73f5dc04f9 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Migrate/d7/MigrateMenuLinkTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Migrate/d7/MigrateMenuLinkTest.php
@@ -18,7 +18,7 @@ class MigrateMenuLinkTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'link',
diff --git a/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php b/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
index 6a7cf4a363..e2daed419d 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/PathAliasMenuLinkContentTest.php
@@ -18,7 +18,7 @@ class PathAliasMenuLinkContentTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'system', 'link', 'test_page_test'];
+  protected static $modules = ['menu_link_content', 'system', 'link', 'test_page_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/process/LinkUriTest.php b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/process/LinkUriTest.php
index 5ae840f766..696428465f 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/process/LinkUriTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/process/LinkUriTest.php
@@ -23,7 +23,7 @@ class LinkUriTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/MenuLinkTest.php b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/MenuLinkTest.php
index 7fb3a918f8..907a9da09a 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/MenuLinkTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/MenuLinkTest.php
@@ -17,7 +17,7 @@ class MenuLinkTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'migrate_drupal'];
+  protected static $modules = ['menu_link_content', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/d6/MenuLinkTranslationTest.php b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/d6/MenuLinkTranslationTest.php
index d373bb2587..303556c858 100644
--- a/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/d6/MenuLinkTranslationTest.php
+++ b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/d6/MenuLinkTranslationTest.php
@@ -15,7 +15,7 @@ class MenuLinkTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'migrate_drupal'];
+  protected static $modules = ['menu_link_content', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_ui/src/Tests/MenuWebTestBase.php b/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
index a8b9862223..6a902c58c7 100644
--- a/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
+++ b/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'menu_link_content'];
+  protected static $modules = ['menu_ui', 'menu_link_content'];
 
   /**
    * Fetches the menu item from the database and compares it to expected item.
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuCacheTagsTest.php b/core/modules/menu_ui/tests/src/Functional/MenuCacheTagsTest.php
index c0d36690bc..5050ca49ad 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuCacheTagsTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuCacheTagsTest.php
@@ -17,7 +17,7 @@ class MenuCacheTagsTest extends PageCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui', 'block', 'test_page_test'];
+  protected static $modules = ['menu_ui', 'block', 'test_page_test'];
 
   /**
    * Tests cache tags presence and invalidation of the Menu entity.
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuLinkReorderTest.php b/core/modules/menu_ui/tests/src/Functional/MenuLinkReorderTest.php
index 4d2bba60d0..d794808963 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuLinkReorderTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuLinkReorderTest.php
@@ -23,7 +23,7 @@ class MenuLinkReorderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'test_page_test', 'node', 'block'];
+  protected static $modules = ['menu_ui', 'test_page_test', 'node', 'block'];
 
   /**
    * Test creating, editing, deleting menu links via node form widget.
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php b/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php
index b5d4b43c82..790ee7c724 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php
@@ -19,7 +19,7 @@ class MenuUiContentModerationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'content_moderation', 'node', 'menu_ui', 'test_page_test'];
+  protected static $modules = ['block', 'content_moderation', 'node', 'menu_ui', 'test_page_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuUiNodeTest.php b/core/modules/menu_ui/tests/src/Functional/MenuUiNodeTest.php
index 7e22bcb46d..1dcf8945a1 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuUiNodeTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuUiNodeTest.php
@@ -26,7 +26,7 @@ class MenuUiNodeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'test_page_test', 'node', 'block', 'locale', 'language', 'content_translation'];
+  protected static $modules = ['menu_ui', 'test_page_test', 'node', 'block', 'locale', 'language', 'content_translation'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/menu_ui/tests/src/Functional/MenuUninstallTest.php b/core/modules/menu_ui/tests/src/Functional/MenuUninstallTest.php
index a0320f44b0..5fea50f59c 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuUninstallTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuUninstallTest.php
@@ -17,7 +17,7 @@ class MenuUninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * Tests Menu uninstall.
diff --git a/core/modules/menu_ui/tests/src/Kernel/Migrate/MigrateMenuSettingsTest.php b/core/modules/menu_ui/tests/src/Kernel/Migrate/MigrateMenuSettingsTest.php
index f87bc5fe78..a3111603cd 100644
--- a/core/modules/menu_ui/tests/src/Kernel/Migrate/MigrateMenuSettingsTest.php
+++ b/core/modules/menu_ui/tests/src/Kernel/Migrate/MigrateMenuSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateMenuSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Functional/process/DownloadFunctionalTest.php b/core/modules/migrate/tests/src/Functional/process/DownloadFunctionalTest.php
index 5e890a0e6a..a9f40dab02 100644
--- a/core/modules/migrate/tests/src/Functional/process/DownloadFunctionalTest.php
+++ b/core/modules/migrate/tests/src/Functional/process/DownloadFunctionalTest.php
@@ -17,7 +17,7 @@ class DownloadFunctionalTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate', 'file'];
+  protected static $modules = ['migrate', 'file'];
 
   /**
    * Tests that an exception is thrown bu migration continues with the next row.
diff --git a/core/modules/migrate/tests/src/Kernel/HighWaterNotJoinableTest.php b/core/modules/migrate/tests/src/Kernel/HighWaterNotJoinableTest.php
index 4198579026..d8d7c1970e 100644
--- a/core/modules/migrate/tests/src/Kernel/HighWaterNotJoinableTest.php
+++ b/core/modules/migrate/tests/src/Kernel/HighWaterNotJoinableTest.php
@@ -13,7 +13,7 @@ class HighWaterNotJoinableTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate', 'migrate_drupal', 'migrate_high_water_test'];
+  protected static $modules = ['migrate', 'migrate_drupal', 'migrate_high_water_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/HighWaterTest.php b/core/modules/migrate/tests/src/Kernel/HighWaterTest.php
index faffb66358..daf4c62365 100644
--- a/core/modules/migrate/tests/src/Kernel/HighWaterTest.php
+++ b/core/modules/migrate/tests/src/Kernel/HighWaterTest.php
@@ -12,7 +12,7 @@ class HighWaterTest extends MigrateTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
     'node',
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateBundleTest.php b/core/modules/migrate/tests/src/Kernel/MigrateBundleTest.php
index b6c3051330..ddecd95fc8 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateBundleTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateBundleTest.php
@@ -18,7 +18,7 @@ class MigrateBundleTest extends MigrateTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'text', 'user'];
+  protected static $modules = ['taxonomy', 'text', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateConfigRollbackTest.php b/core/modules/migrate/tests/src/Kernel/MigrateConfigRollbackTest.php
index 27aa45bcce..13d604a734 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateConfigRollbackTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateConfigRollbackTest.php
@@ -16,7 +16,7 @@ class MigrateConfigRollbackTest extends MigrateTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'language', 'config_translation'];
+  protected static $modules = ['system', 'language', 'config_translation'];
 
   /**
    * Tests rolling back configuration.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateEmbeddedDataTest.php b/core/modules/migrate/tests/src/Kernel/MigrateEmbeddedDataTest.php
index 019ac42ab9..0f02bcd985 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateEmbeddedDataTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateEmbeddedDataTest.php
@@ -16,7 +16,7 @@ class MigrateEmbeddedDataTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * Tests the embedded_data source plugin.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php b/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php
index 13803bd211..85a563bf12 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php
@@ -24,7 +24,7 @@ class MigrateEntityContentBaseTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate', 'user', 'language', 'entity_test'];
+  protected static $modules = ['migrate', 'user', 'language', 'entity_test'];
 
   /**
    * The storage for entity_test_mul.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateEventsTest.php b/core/modules/migrate/tests/src/Kernel/MigrateEventsTest.php
index 8dc4aa9ad4..bd94e30c21 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateEventsTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateEventsTest.php
@@ -30,7 +30,7 @@ class MigrateEventsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate', 'migrate_events_test'];
+  protected static $modules = ['migrate', 'migrate_events_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateExternalTranslatedTest.php b/core/modules/migrate/tests/src/Kernel/MigrateExternalTranslatedTest.php
index d9728f587e..8f87bafdfc 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateExternalTranslatedTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateExternalTranslatedTest.php
@@ -19,7 +19,7 @@ class MigrateExternalTranslatedTest extends MigrateTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'language', 'node', 'field', 'migrate_external_translated_test'];
+  protected static $modules = ['system', 'user', 'language', 'node', 'field', 'migrate_external_translated_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateInterruptionTest.php b/core/modules/migrate/tests/src/Kernel/MigrateInterruptionTest.php
index 207af4d8e1..d451d050fd 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateInterruptionTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateInterruptionTest.php
@@ -20,7 +20,7 @@ class MigrateInterruptionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate', 'migrate_events_test'];
+  protected static $modules = ['migrate', 'migrate_events_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateMessageTest.php b/core/modules/migrate/tests/src/Kernel/MigrateMessageTest.php
index 33013367e9..ad0890418d 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateMessageTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateMessageTest.php
@@ -21,7 +21,7 @@ class MigrateMessageTest extends KernelTestBase implements MigrateMessageInterfa
    *
    * @var array
    */
-  public static $modules = ['migrate', 'system'];
+  protected static $modules = ['migrate', 'system'];
 
   /**
    * Migration to run.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateRollbackEntityConfigTest.php b/core/modules/migrate/tests/src/Kernel/MigrateRollbackEntityConfigTest.php
index d43ad8af58..0a54a817e2 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateRollbackEntityConfigTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateRollbackEntityConfigTest.php
@@ -17,7 +17,7 @@ class MigrateRollbackEntityConfigTest extends MigrateTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'taxonomy', 'text', 'language', 'config_translation', 'user'];
+  protected static $modules = ['field', 'taxonomy', 'text', 'language', 'config_translation', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
index de1666be63..25b58f91ab 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateRollbackTest.php
@@ -20,7 +20,7 @@ class MigrateRollbackTest extends MigrateTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'taxonomy', 'text', 'user'];
+  protected static $modules = ['field', 'taxonomy', 'text', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateSkipRowTest.php b/core/modules/migrate/tests/src/Kernel/MigrateSkipRowTest.php
index 8c5e01e513..4a7a3e8c19 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateSkipRowTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateSkipRowTest.php
@@ -19,7 +19,7 @@ class MigrateSkipRowTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate', 'migrate_prepare_row_test'];
+  protected static $modules = ['migrate', 'migrate_prepare_row_test'];
 
   /**
    * Tests migration interruptions.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateSourceTestBase.php b/core/modules/migrate/tests/src/Kernel/MigrateSourceTestBase.php
index c4bd6cd5e0..3dcd26f65f 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateSourceTestBase.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateSourceTestBase.php
@@ -15,7 +15,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * The mocked migration.
diff --git a/core/modules/migrate/tests/src/Kernel/MigrateTestBase.php b/core/modules/migrate/tests/src/Kernel/MigrateTestBase.php
index 51e61d40ca..e44bdb9716 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateTestBase.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateTestBase.php
@@ -47,7 +47,7 @@
    */
   protected $sourceDatabase;
 
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/MigrationTest.php b/core/modules/migrate/tests/src/Kernel/MigrationTest.php
index 5fe56ecf95..72b5b2444d 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrationTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrationTest.php
@@ -18,7 +18,7 @@ class MigrationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate', 'field'];
+  protected static $modules = ['migrate', 'field'];
 
   /**
    * Tests Migration::set().
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/EntityExistsTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/EntityExistsTest.php
index dcd070c337..242f54c353 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/EntityExistsTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/EntityExistsTest.php
@@ -17,7 +17,7 @@ class EntityExistsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate', 'system', 'user'];
+  protected static $modules = ['migrate', 'system', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/EntityRevisionTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/EntityRevisionTest.php
index d15446fbad..2e2d42ad6b 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/EntityRevisionTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/EntityRevisionTest.php
@@ -19,7 +19,7 @@ class EntityRevisionTest extends MigrateTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'field',
     'filter',
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/LogTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/LogTest.php
index bb5d04dbd1..85b125604c 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/LogTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/LogTest.php
@@ -16,7 +16,7 @@ class LogTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * Test the Log plugin.
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationDirectoryTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationDirectoryTest.php
index b85aea478f..a21b3037f2 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationDirectoryTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationDirectoryTest.php
@@ -15,7 +15,7 @@ class MigrationDirectoryTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migration_directory_test'];
+  protected static $modules = ['migration_directory_test'];
 
   /**
    * Tests that migrations in the migration_templates directory are created.
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginConfigurationTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginConfigurationTest.php
index 827af91ee6..0f789bbc49 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginConfigurationTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginConfigurationTest.php
@@ -15,7 +15,7 @@ class MigrationPluginConfigurationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'migrate',
     'migrate_drupal',
     // Test with a simple migration.
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php
index 7bfba70f27..2e41834601 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php
@@ -22,7 +22,7 @@ class MigrationPluginListTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'migrate',
     // Test with all modules containing Drupal migrations.
     'action',
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
index a8dddd277a..c2f678601a 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
@@ -17,7 +17,7 @@ class MigrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * Tests Migration::getProcessPlugins()
diff --git a/core/modules/migrate/tests/src/Kernel/QueryBatchTest.php b/core/modules/migrate/tests/src/Kernel/QueryBatchTest.php
index e92e1441e1..58f3c25891 100644
--- a/core/modules/migrate/tests/src/Kernel/QueryBatchTest.php
+++ b/core/modules/migrate/tests/src/Kernel/QueryBatchTest.php
@@ -26,7 +26,7 @@ class QueryBatchTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'migrate',
     'migrate_query_batch_test',
   ];
diff --git a/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php b/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php
index 11674c0bc2..23a1ae7d65 100644
--- a/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php
@@ -20,7 +20,7 @@ class DownloadTest extends FileTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate/tests/src/Kernel/process/ExtractTest.php b/core/modules/migrate/tests/src/Kernel/process/ExtractTest.php
index 9338b9e3c9..8dc73f4924 100644
--- a/core/modules/migrate/tests/src/Kernel/process/ExtractTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/ExtractTest.php
@@ -16,7 +16,7 @@ class ExtractTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * Returns test migration definition.
diff --git a/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php b/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php
index e107f41574..e07db9a714 100644
--- a/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php
@@ -23,7 +23,7 @@ class FileCopyTest extends FileTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate', 'system'];
+  protected static $modules = ['migrate', 'system'];
 
   /**
    * The file system service.
diff --git a/core/modules/migrate/tests/src/Kernel/process/HandleMultiplesTest.php b/core/modules/migrate/tests/src/Kernel/process/HandleMultiplesTest.php
index dc63de3db6..caae69de61 100644
--- a/core/modules/migrate/tests/src/Kernel/process/HandleMultiplesTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/HandleMultiplesTest.php
@@ -16,7 +16,7 @@ class HandleMultiplesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate'];
+  protected static $modules = ['migrate'];
 
   /**
    * Provides the test migration definition.
diff --git a/core/modules/migrate/tests/src/Kernel/process/RouteTest.php b/core/modules/migrate/tests/src/Kernel/process/RouteTest.php
index 3f212356db..0d1c687ed1 100644
--- a/core/modules/migrate/tests/src/Kernel/process/RouteTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/RouteTest.php
@@ -21,7 +21,7 @@ class RouteTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * Tests Route plugin based on providerTestRoute() values.
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php b/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php
index 60e08e5a9e..f89ac847a4 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php
@@ -14,7 +14,7 @@ class CckFieldBackwardsCompatibilityTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'migrate_cckfield_plugin_manager_test'];
+  protected static $modules = ['file', 'migrate_cckfield_plugin_manager_test'];
 
   /**
    * Ensures that the cckfield backwards compatibility layer is invoked.
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/MigrateCckFieldPluginManagerTest.php b/core/modules/migrate_drupal/tests/src/Kernel/MigrateCckFieldPluginManagerTest.php
index 7eb68ba338..cbcd929d90 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/MigrateCckFieldPluginManagerTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/MigrateCckFieldPluginManagerTest.php
@@ -14,7 +14,7 @@ class MigrateCckFieldPluginManagerTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'text', 'migrate_cckfield_plugin_manager_test'];
+  protected static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'text', 'migrate_cckfield_plugin_manager_test'];
 
   /**
    * Tests that the correct MigrateCckField plugins are used.
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php b/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php
index 063c99cb36..e091b1c525 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php
@@ -15,7 +15,7 @@
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file'];
+  protected static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
index 284a267a1f..415d9d91ea 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
@@ -14,7 +14,7 @@ class MigrateFieldPluginManagerTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'image', 'text', 'link', 'migrate_field_plugin_manager_test'];
+  protected static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'image', 'text', 'link', 'migrate_field_plugin_manager_test'];
 
   /**
    * Tests that the correct MigrateField plugins are used.
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
index 1bcedcfa67..7b508b119a 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
@@ -32,7 +32,7 @@ class ContentEntityTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'user',
     'migrate',
     'migrate_drupal',
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableMultiRowTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableMultiRowTest.php
index 932af99037..bf72ed11b5 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableMultiRowTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableMultiRowTest.php
@@ -16,7 +16,7 @@ class VariableMultiRowTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal'];
+  protected static $modules = ['migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableTest.php
index b68c4b467b..71a80a7965 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableTest.php
@@ -16,7 +16,7 @@ class VariableTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal'];
+  protected static $modules = ['migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d6/i18nVariableTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d6/i18nVariableTest.php
index 8c3e6044eb..8a163cd6ad 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d6/i18nVariableTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d6/i18nVariableTest.php
@@ -16,7 +16,7 @@ class i18nVariableTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal'];
+  protected static $modules = ['migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d8/ConfigTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d8/ConfigTest.php
index 3cf4031907..0cb0dcf5d8 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d8/ConfigTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/d8/ConfigTest.php
@@ -15,7 +15,7 @@ class ConfigTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal'];
+  protected static $modules = ['migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d6/EntityContentBaseTest.php b/core/modules/migrate_drupal/tests/src/Kernel/d6/EntityContentBaseTest.php
index db44c63450..3dfba9d5ce 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d6/EntityContentBaseTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d6/EntityContentBaseTest.php
@@ -17,7 +17,7 @@ class EntityContentBaseTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_overwrite_test'];
+  protected static $modules = ['migrate_overwrite_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php b/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php
index 5225ce5d83..37d2f44b1b 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php
@@ -15,7 +15,7 @@ class FollowUpMigrationsTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6TestBase.php b/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6TestBase.php
index 3a9467e037..e7dcd863d9 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6TestBase.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6TestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'datetime',
     'filter',
     'image',
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/d7/FollowUpMigrationsTest.php b/core/modules/migrate_drupal/tests/src/Kernel/d7/FollowUpMigrationsTest.php
index 5417df4772..d5e7754507 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/d7/FollowUpMigrationsTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/d7/FollowUpMigrationsTest.php
@@ -17,7 +17,7 @@ class FollowUpMigrationsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'comment',
     'datetime',
diff --git a/core/modules/migrate_drupal/tests/src/Kernel/dependencies/MigrateDependenciesTest.php b/core/modules/migrate_drupal/tests/src/Kernel/dependencies/MigrateDependenciesTest.php
index 3fa00568b5..b82bfb1a4c 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/dependencies/MigrateDependenciesTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/dependencies/MigrateDependenciesTest.php
@@ -16,7 +16,7 @@ class MigrateDependenciesTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator', 'comment'];
+  protected static $modules = ['aggregator', 'comment'];
 
   /**
    * Tests that the order is correct when loading several migrations.
diff --git a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
index 35ea71d309..78cc261752 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
@@ -37,7 +37,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'migrate_drupal_ui',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateAccessTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateAccessTest.php
index 3c475e2068..307f75e8bc 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateAccessTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateAccessTest.php
@@ -16,7 +16,7 @@ class MigrateAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['migrate_drupal_ui'];
+  protected static $modules = ['migrate_drupal_ui'];
 
   /**
    * Tests that only user 1 can access the migrate UI.
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeFormStepsTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeFormStepsTest.php
index caa60c3438..8bc693827e 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeFormStepsTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeFormStepsTest.php
@@ -20,7 +20,7 @@ class MigrateUpgradeFormStepsTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal_ui'];
+  protected static $modules = ['migrate_drupal_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
index 5c97a69070..fb3c084717 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
@@ -21,7 +21,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal_ui'];
+  protected static $modules = ['migrate_drupal_ui'];
 
   /**
    * Tests the migrate upgrade review form.
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6I18nReviewPageTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6I18nReviewPageTest.php
index a4deaa25cf..e9f8c6303c 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6I18nReviewPageTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6I18nReviewPageTest.php
@@ -15,7 +15,7 @@ class MigrateUpgrade6I18nReviewPageTest extends MigrateUpgradeI18nReviewPageTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'telephone',
     'aggregator',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6NoMultilingualTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6NoMultilingualTest.php
index e07e8bf211..a5f58a029b 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6NoMultilingualTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6NoMultilingualTest.php
@@ -16,7 +16,7 @@ class MigrateUpgrade6NoMultilingualTest extends MigrateUpgradeExecuteTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'config_translation',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6ReviewPageTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6ReviewPageTest.php
index d2fe095b50..1993730662 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6ReviewPageTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6ReviewPageTest.php
@@ -15,7 +15,7 @@ class MigrateUpgrade6ReviewPageTest extends MigrateUpgradeReviewPageTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'config_translation',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
index d8ffd02964..5c1e7a4aef 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
@@ -20,7 +20,7 @@ class MigrateUpgrade6Test extends MigrateUpgradeExecuteTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'config_translation',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7NoMultilingualTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7NoMultilingualTest.php
index 350c10295c..203ee68fe4 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7NoMultilingualTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7NoMultilingualTest.php
@@ -16,7 +16,7 @@ class MigrateUpgrade7NoMultilingualTest extends MigrateUpgradeExecuteTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'file',
     'language',
     'content_translation',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7ReviewPageTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7ReviewPageTest.php
index c1686db643..7529b71161 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7ReviewPageTest.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7ReviewPageTest.php
@@ -15,7 +15,7 @@ class MigrateUpgrade7ReviewPageTest extends MigrateUpgradeReviewPageTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'telephone',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
index c5fbacc1a1..f38d954456 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
@@ -20,7 +20,7 @@ class MigrateUpgrade7Test extends MigrateUpgradeExecuteTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'file',
     'language',
     'content_translation',
diff --git a/core/modules/node/src/Tests/NodeRevisionsTest.php b/core/modules/node/src/Tests/NodeRevisionsTest.php
index fdc929a84c..a5ef4a0c27 100644
--- a/core/modules/node/src/Tests/NodeRevisionsTest.php
+++ b/core/modules/node/src/Tests/NodeRevisionsTest.php
@@ -35,7 +35,7 @@ class NodeRevisionsTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'contextual', 'datetime', 'language', 'content_translation'];
+  protected static $modules = ['node', 'contextual', 'datetime', 'language', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/src/Tests/NodeTestBase.php b/core/modules/node/src/Tests/NodeTestBase.php
index 643684cde4..c1fbf44156 100644
--- a/core/modules/node/src/Tests/NodeTestBase.php
+++ b/core/modules/node/src/Tests/NodeTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'datetime'];
+  protected static $modules = ['node', 'datetime'];
 
   /**
    * The node access control handler.
diff --git a/core/modules/node/src/Tests/NodeTypeTest.php b/core/modules/node/src/Tests/NodeTypeTest.php
index 9938bb0ab5..b23d208d02 100644
--- a/core/modules/node/src/Tests/NodeTypeTest.php
+++ b/core/modules/node/src/Tests/NodeTypeTest.php
@@ -21,7 +21,7 @@ class NodeTypeTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui', 'block'];
+  protected static $modules = ['field_ui', 'block'];
 
   /**
    * Ensures that node type functions (node_type_get_*) work correctly.
diff --git a/core/modules/node/src/Tests/PagePreviewTest.php b/core/modules/node/src/Tests/PagePreviewTest.php
index 2bc9cd3ce1..105d0dad03 100644
--- a/core/modules/node/src/Tests/PagePreviewTest.php
+++ b/core/modules/node/src/Tests/PagePreviewTest.php
@@ -28,7 +28,7 @@ class PagePreviewTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'taxonomy', 'comment', 'image', 'file', 'text', 'node_test', 'menu_ui'];
+  protected static $modules = ['node', 'taxonomy', 'comment', 'image', 'file', 'text', 'node_test', 'menu_ui'];
 
   /**
    * The name of the created field.
diff --git a/core/modules/node/src/Tests/Views/NodeContextualLinksTest.php b/core/modules/node/src/Tests/Views/NodeContextualLinksTest.php
index dc23d0ce55..38578e37e0 100644
--- a/core/modules/node/src/Tests/Views/NodeContextualLinksTest.php
+++ b/core/modules/node/src/Tests/Views/NodeContextualLinksTest.php
@@ -17,7 +17,7 @@ class NodeContextualLinksTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['contextual'];
+  protected static $modules = ['contextual'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/src/Tests/Views/NodeTestBase.php b/core/modules/node/src/Tests/Views/NodeTestBase.php
index cb765d4c56..652d3ce82c 100644
--- a/core/modules/node/src/Tests/Views/NodeTestBase.php
+++ b/core/modules/node/src/Tests/Views/NodeTestBase.php
@@ -20,7 +20,7 @@
    *
    * @var array
    */
-  public static $modules = ['node_test_views'];
+  protected static $modules = ['node_test_views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/node/tests/src/Functional/Hal/NodeHalJsonAnonTest.php b/core/modules/node/tests/src/Functional/Hal/NodeHalJsonAnonTest.php
index f474c54f7c..e684f62475 100644
--- a/core/modules/node/tests/src/Functional/Hal/NodeHalJsonAnonTest.php
+++ b/core/modules/node/tests/src/Functional/Hal/NodeHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class NodeHalJsonAnonTest extends NodeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Hal/NodeHalJsonBasicAuthTest.php b/core/modules/node/tests/src/Functional/Hal/NodeHalJsonBasicAuthTest.php
index 0c973a168e..5e53e251d7 100644
--- a/core/modules/node/tests/src/Functional/Hal/NodeHalJsonBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Hal/NodeHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class NodeHalJsonBasicAuthTest extends NodeHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonAnonTest.php b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonAnonTest.php
index 68f531c89e..7db4183fed 100644
--- a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonAnonTest.php
+++ b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class NodeTypeHalJsonAnonTest extends NodeTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonBasicAuthTest.php b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonBasicAuthTest.php
index fb7098bdc4..4f74b16763 100644
--- a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class NodeTypeHalJsonBasicAuthTest extends NodeTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonCookieTest.php b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonCookieTest.php
index 9d7f5a9a32..b74f71ee90 100644
--- a/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonCookieTest.php
+++ b/core/modules/node/tests/src/Functional/Hal/NodeTypeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class NodeTypeHalJsonCookieTest extends NodeTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Migrate/d6/MigrateNodeRevisionTest.php b/core/modules/node/tests/src/Functional/Migrate/d6/MigrateNodeRevisionTest.php
index 4065278bcf..27a294daf3 100644
--- a/core/modules/node/tests/src/Functional/Migrate/d6/MigrateNodeRevisionTest.php
+++ b/core/modules/node/tests/src/Functional/Migrate/d6/MigrateNodeRevisionTest.php
@@ -14,7 +14,7 @@ class MigrateNodeRevisionTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'content_translation', 'menu_ui'];
+  protected static $modules = ['language', 'content_translation', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Migrate/d7/NodeMigrateDeriverTest.php b/core/modules/node/tests/src/Functional/Migrate/d7/NodeMigrateDeriverTest.php
index 621cdb6d49..fb9ed7a6d9 100644
--- a/core/modules/node/tests/src/Functional/Migrate/d7/NodeMigrateDeriverTest.php
+++ b/core/modules/node/tests/src/Functional/Migrate/d7/NodeMigrateDeriverTest.php
@@ -11,7 +11,7 @@
  */
 class NodeMigrateDeriverTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   public function testBuilder() {
     $process = $this->getMigration('d7_node:test_content_type')->getProcess();
diff --git a/core/modules/node/tests/src/Functional/NodeAccessAutoBubblingTest.php b/core/modules/node/tests/src/Functional/NodeAccessAutoBubblingTest.php
index 20154553fc..6e2a2ae2af 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessAutoBubblingTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessAutoBubblingTest.php
@@ -21,7 +21,7 @@ class NodeAccessAutoBubblingTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test', 'node_access_test_auto_bubbling'];
+  protected static $modules = ['node_access_test', 'node_access_test_auto_bubbling'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/NodeAccessBaseTableTest.php b/core/modules/node/tests/src/Functional/NodeAccessBaseTableTest.php
index d9e4e8b092..cd8040ba89 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessBaseTableTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessBaseTableTest.php
@@ -16,7 +16,7 @@ class NodeAccessBaseTableTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test', 'views'];
+  protected static $modules = ['node_access_test', 'views'];
 
   /**
    * The installation profile to use with this test.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php b/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php
index ab6f28df94..6b16bf142a 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php
@@ -17,7 +17,7 @@ class NodeAccessFieldTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test', 'field_ui'];
+  protected static $modules = ['node_access_test', 'field_ui'];
 
   /**
    * A user with permission to bypass access content.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
index fa2116ab87..0a5da3e6b3 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
@@ -15,7 +15,7 @@ class NodeAccessGrantsCacheContextTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test'];
+  protected static $modules = ['node_access_test'];
 
   /**
    * User with permission to view content.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareCombinationTest.php b/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareCombinationTest.php
index bc78291e3f..c9716c02b8 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareCombinationTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareCombinationTest.php
@@ -22,7 +22,7 @@ class NodeAccessLanguageAwareCombinationTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node_access_test_language', 'node_access_test'];
+  protected static $modules = ['language', 'node_access_test_language', 'node_access_test'];
 
   /**
    * A set of nodes to use in testing.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareTest.php b/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareTest.php
index 48f9dfac36..f041d2438c 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessLanguageAwareTest.php
@@ -21,7 +21,7 @@ class NodeAccessLanguageAwareTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node_access_test_language'];
+  protected static $modules = ['language', 'node_access_test_language'];
 
   /**
    * A set of nodes to use in testing.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessLanguageFallbackTest.php b/core/modules/node/tests/src/Functional/NodeAccessLanguageFallbackTest.php
index 4beacc3423..bc37dd29bd 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessLanguageFallbackTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessLanguageFallbackTest.php
@@ -16,7 +16,7 @@ class NodeAccessLanguageFallbackTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node_access_test', 'content_translation'];
+  protected static $modules = ['language', 'node_access_test', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/NodeAccessLanguageTest.php b/core/modules/node/tests/src/Functional/NodeAccessLanguageTest.php
index 1af5660fe5..5aadddbefa 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessLanguageTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessLanguageTest.php
@@ -20,7 +20,7 @@ class NodeAccessLanguageTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'node_access_test'];
+  protected static $modules = ['language', 'node_access_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php b/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
index 5d987b36a1..53f2dc0cd6 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessMenuLinkTest.php
@@ -16,7 +16,7 @@ class NodeAccessMenuLinkTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'block'];
+  protected static $modules = ['menu_ui', 'block'];
 
   /**
    * A user with permission to manage menu links and create nodes.
diff --git a/core/modules/node/tests/src/Functional/NodeAccessPagerTest.php b/core/modules/node/tests/src/Functional/NodeAccessPagerTest.php
index ad6cc54944..ef685c620b 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessPagerTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessPagerTest.php
@@ -21,7 +21,7 @@ class NodeAccessPagerTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test', 'comment', 'forum'];
+  protected static $modules = ['node_access_test', 'comment', 'forum'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeAccessRecordsTest.php b/core/modules/node/tests/src/Functional/NodeAccessRecordsTest.php
index 259ed83efb..853d7f34c9 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessRecordsTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessRecordsTest.php
@@ -16,7 +16,7 @@ class NodeAccessRecordsTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test'];
+  protected static $modules = ['node_test'];
 
   /**
    * Creates a node and tests the creation of node access rules.
diff --git a/core/modules/node/tests/src/Functional/NodeActionsConfigurationTest.php b/core/modules/node/tests/src/Functional/NodeActionsConfigurationTest.php
index d026902f57..9ff6b79253 100644
--- a/core/modules/node/tests/src/Functional/NodeActionsConfigurationTest.php
+++ b/core/modules/node/tests/src/Functional/NodeActionsConfigurationTest.php
@@ -17,7 +17,7 @@ class NodeActionsConfigurationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['action', 'node'];
+  protected static $modules = ['action', 'node'];
 
   /**
    * Tests configuration of the node_assign_owner_action action.
diff --git a/core/modules/node/tests/src/Functional/NodeAdminTest.php b/core/modules/node/tests/src/Functional/NodeAdminTest.php
index 24a50cf51a..9417ba186b 100644
--- a/core/modules/node/tests/src/Functional/NodeAdminTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAdminTest.php
@@ -43,7 +43,7 @@ class NodeAdminTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeBlockFunctionalTest.php b/core/modules/node/tests/src/Functional/NodeBlockFunctionalTest.php
index c6f786df8e..f31da661a6 100644
--- a/core/modules/node/tests/src/Functional/NodeBlockFunctionalTest.php
+++ b/core/modules/node/tests/src/Functional/NodeBlockFunctionalTest.php
@@ -35,7 +35,7 @@ class NodeBlockFunctionalTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'views'];
+  protected static $modules = ['block', 'views'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeCacheTagsTest.php b/core/modules/node/tests/src/Functional/NodeCacheTagsTest.php
index 6cda724cc4..b7b8e87e56 100644
--- a/core/modules/node/tests/src/Functional/NodeCacheTagsTest.php
+++ b/core/modules/node/tests/src/Functional/NodeCacheTagsTest.php
@@ -17,7 +17,7 @@ class NodeCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
index 0d4aabe6a0..3ec8140e23 100644
--- a/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
+++ b/core/modules/node/tests/src/Functional/NodeContextualLinksTest.php
@@ -14,7 +14,7 @@ class NodeContextualLinksTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
   ];
 
diff --git a/core/modules/node/tests/src/Functional/NodeCreationTest.php b/core/modules/node/tests/src/Functional/NodeCreationTest.php
index 1ea8fcc332..c555fcb216 100644
--- a/core/modules/node/tests/src/Functional/NodeCreationTest.php
+++ b/core/modules/node/tests/src/Functional/NodeCreationTest.php
@@ -21,7 +21,7 @@ class NodeCreationTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test_exception', 'dblog', 'test_page_test'];
+  protected static $modules = ['node_test_exception', 'dblog', 'test_page_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeEditFormTest.php b/core/modules/node/tests/src/Functional/NodeEditFormTest.php
index c15ca70bbe..be70c15f61 100644
--- a/core/modules/node/tests/src/Functional/NodeEditFormTest.php
+++ b/core/modules/node/tests/src/Functional/NodeEditFormTest.php
@@ -38,7 +38,7 @@ class NodeEditFormTest extends NodeTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block', 'node', 'datetime'];
+  protected static $modules = ['block', 'node', 'datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeEntityViewModeAlterTest.php b/core/modules/node/tests/src/Functional/NodeEntityViewModeAlterTest.php
index be0f1c0623..f2294b78b0 100644
--- a/core/modules/node/tests/src/Functional/NodeEntityViewModeAlterTest.php
+++ b/core/modules/node/tests/src/Functional/NodeEntityViewModeAlterTest.php
@@ -17,7 +17,7 @@ class NodeEntityViewModeAlterTest extends NodeTestBase {
   /**
    * Enable dummy module that implements hook_ENTITY_TYPE_view() for nodes.
    */
-  public static $modules = ['node_test'];
+  protected static $modules = ['node_test'];
 
   /**
    * Create a "Basic page" node and verify its consistency in the database.
diff --git a/core/modules/node/tests/src/Functional/NodeFieldMultilingualTest.php b/core/modules/node/tests/src/Functional/NodeFieldMultilingualTest.php
index 771426d025..ba59e03024 100644
--- a/core/modules/node/tests/src/Functional/NodeFieldMultilingualTest.php
+++ b/core/modules/node/tests/src/Functional/NodeFieldMultilingualTest.php
@@ -20,7 +20,7 @@ class NodeFieldMultilingualTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'language'];
+  protected static $modules = ['node', 'language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeFormSaveChangedTimeTest.php b/core/modules/node/tests/src/Functional/NodeFormSaveChangedTimeTest.php
index 607e68cf0d..7c4fb4b660 100644
--- a/core/modules/node/tests/src/Functional/NodeFormSaveChangedTimeTest.php
+++ b/core/modules/node/tests/src/Functional/NodeFormSaveChangedTimeTest.php
@@ -16,7 +16,7 @@ class NodeFormSaveChangedTimeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
   ];
 
diff --git a/core/modules/node/tests/src/Functional/NodeHelpTest.php b/core/modules/node/tests/src/Functional/NodeHelpTest.php
index 4dad416185..50773a9efd 100644
--- a/core/modules/node/tests/src/Functional/NodeHelpTest.php
+++ b/core/modules/node/tests/src/Functional/NodeHelpTest.php
@@ -16,7 +16,7 @@ class NodeHelpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'help'];
+  protected static $modules = ['block', 'node', 'help'];
 
   /**
    * The name of the test node type to create.
diff --git a/core/modules/node/tests/src/Functional/NodeLinksTest.php b/core/modules/node/tests/src/Functional/NodeLinksTest.php
index 7bd725b46b..0950e14ede 100644
--- a/core/modules/node/tests/src/Functional/NodeLinksTest.php
+++ b/core/modules/node/tests/src/Functional/NodeLinksTest.php
@@ -16,7 +16,7 @@ class NodeLinksTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * Tests that the links can be hidden in the view display settings.
diff --git a/core/modules/node/tests/src/Functional/NodeLoadMultipleTest.php b/core/modules/node/tests/src/Functional/NodeLoadMultipleTest.php
index 2da5d1bbeb..9db35c209c 100644
--- a/core/modules/node/tests/src/Functional/NodeLoadMultipleTest.php
+++ b/core/modules/node/tests/src/Functional/NodeLoadMultipleTest.php
@@ -16,7 +16,7 @@ class NodeLoadMultipleTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodePreviewAnonymousTest.php b/core/modules/node/tests/src/Functional/NodePreviewAnonymousTest.php
index f10d8b7389..4386b797b1 100644
--- a/core/modules/node/tests/src/Functional/NodePreviewAnonymousTest.php
+++ b/core/modules/node/tests/src/Functional/NodePreviewAnonymousTest.php
@@ -18,7 +18,7 @@ class NodePreviewAnonymousTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
index 362a27fc48..1c3503a7cc 100644
--- a/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
+++ b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
@@ -14,7 +14,7 @@ class NodeQueryAlterTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_access_test'];
+  protected static $modules = ['node_access_test'];
 
   /**
    * User with permission to view content.
diff --git a/core/modules/node/tests/src/Functional/NodeRSSContentTest.php b/core/modules/node/tests/src/Functional/NodeRSSContentTest.php
index 0efa336ade..77015607f6 100644
--- a/core/modules/node/tests/src/Functional/NodeRSSContentTest.php
+++ b/core/modules/node/tests/src/Functional/NodeRSSContentTest.php
@@ -20,7 +20,7 @@ class NodeRSSContentTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test', 'views'];
+  protected static $modules = ['node_test', 'views'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeRevisionsUiBypassAccessTest.php b/core/modules/node/tests/src/Functional/NodeRevisionsUiBypassAccessTest.php
index 186b694774..e120f12706 100644
--- a/core/modules/node/tests/src/Functional/NodeRevisionsUiBypassAccessTest.php
+++ b/core/modules/node/tests/src/Functional/NodeRevisionsUiBypassAccessTest.php
@@ -25,7 +25,7 @@ class NodeRevisionsUiBypassAccessTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/NodeSaveTest.php b/core/modules/node/tests/src/Functional/NodeSaveTest.php
index 6c508aee68..f12e6126c8 100644
--- a/core/modules/node/tests/src/Functional/NodeSaveTest.php
+++ b/core/modules/node/tests/src/Functional/NodeSaveTest.php
@@ -23,7 +23,7 @@ class NodeSaveTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test'];
+  protected static $modules = ['node_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeSyndicateBlockTest.php b/core/modules/node/tests/src/Functional/NodeSyndicateBlockTest.php
index c1daef94c9..03fe59f8cb 100644
--- a/core/modules/node/tests/src/Functional/NodeSyndicateBlockTest.php
+++ b/core/modules/node/tests/src/Functional/NodeSyndicateBlockTest.php
@@ -14,7 +14,7 @@ class NodeSyndicateBlockTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeTestBase.php b/core/modules/node/tests/src/Functional/NodeTestBase.php
index e52708632b..ca270e73a8 100644
--- a/core/modules/node/tests/src/Functional/NodeTestBase.php
+++ b/core/modules/node/tests/src/Functional/NodeTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'datetime'];
+  protected static $modules = ['node', 'datetime'];
 
   /**
    * The node access control handler.
diff --git a/core/modules/node/tests/src/Functional/NodeTitleTest.php b/core/modules/node/tests/src/Functional/NodeTitleTest.php
index 8c94f795ad..405247fcfe 100644
--- a/core/modules/node/tests/src/Functional/NodeTitleTest.php
+++ b/core/modules/node/tests/src/Functional/NodeTitleTest.php
@@ -19,7 +19,7 @@ class NodeTitleTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'views', 'block'];
+  protected static $modules = ['comment', 'views', 'block'];
 
   /**
    * A user with permission to bypass access content.
diff --git a/core/modules/node/tests/src/Functional/NodeTranslationUITest.php b/core/modules/node/tests/src/Functional/NodeTranslationUITest.php
index 513c074932..0ab20a08fb 100644
--- a/core/modules/node/tests/src/Functional/NodeTranslationUITest.php
+++ b/core/modules/node/tests/src/Functional/NodeTranslationUITest.php
@@ -37,7 +37,7 @@ class NodeTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'language', 'content_translation', 'node', 'datetime', 'field_ui', 'help'];
+  protected static $modules = ['block', 'language', 'content_translation', 'node', 'datetime', 'field_ui', 'help'];
 
   /**
    * The profile to install as a basis for testing.
diff --git a/core/modules/node/tests/src/Functional/NodeTypeInitialLanguageTest.php b/core/modules/node/tests/src/Functional/NodeTypeInitialLanguageTest.php
index 9c442fd5da..698e14bf5a 100644
--- a/core/modules/node/tests/src/Functional/NodeTypeInitialLanguageTest.php
+++ b/core/modules/node/tests/src/Functional/NodeTypeInitialLanguageTest.php
@@ -16,7 +16,7 @@ class NodeTypeInitialLanguageTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'field_ui'];
+  protected static $modules = ['language', 'field_ui'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php b/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php
index 973955c5dd..613f0443b2 100644
--- a/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php
+++ b/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php
@@ -21,7 +21,7 @@ class NodeTypeTranslationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'config_translation',
     'field_ui',
diff --git a/core/modules/node/tests/src/Functional/NodeViewLanguageTest.php b/core/modules/node/tests/src/Functional/NodeViewLanguageTest.php
index 4730427560..205fbbf437 100644
--- a/core/modules/node/tests/src/Functional/NodeViewLanguageTest.php
+++ b/core/modules/node/tests/src/Functional/NodeViewLanguageTest.php
@@ -16,7 +16,7 @@ class NodeViewLanguageTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'datetime', 'language'];
+  protected static $modules = ['node', 'datetime', 'language'];
 
   /**
    * Tests the language extra field display.
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeJsonBasicAuthTest.php b/core/modules/node/tests/src/Functional/Rest/NodeJsonBasicAuthTest.php
index d4ce479c21..ccd88f9f79 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeJsonBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class NodeJsonBasicAuthTest extends NodeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeResourceTestBase.php b/core/modules/node/tests/src/Functional/Rest/NodeResourceTestBase.php
index 9f9a114924..452d089820 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeResourceTestBase.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeTypeJsonBasicAuthTest.php b/core/modules/node/tests/src/Functional/Rest/NodeTypeJsonBasicAuthTest.php
index e1874e4cc6..ab68c8934b 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeTypeJsonBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeTypeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class NodeTypeJsonBasicAuthTest extends NodeTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeTypeResourceTestBase.php b/core/modules/node/tests/src/Functional/Rest/NodeTypeResourceTestBase.php
index d74824dd13..b2c30174cd 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeTypeResourceTestBase.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeTypeResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeTypeXmlBasicAuthTest.php b/core/modules/node/tests/src/Functional/Rest/NodeTypeXmlBasicAuthTest.php
index 29413dc9c2..2408566d06 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeTypeXmlBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeTypeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class NodeTypeXmlBasicAuthTest extends NodeTypeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Rest/NodeXmlBasicAuthTest.php b/core/modules/node/tests/src/Functional/Rest/NodeXmlBasicAuthTest.php
index ce809747aa..92bb3a6364 100644
--- a/core/modules/node/tests/src/Functional/Rest/NodeXmlBasicAuthTest.php
+++ b/core/modules/node/tests/src/Functional/Rest/NodeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class NodeXmlBasicAuthTest extends NodeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Views/BulkFormAccessTest.php b/core/modules/node/tests/src/Functional/Views/BulkFormAccessTest.php
index 19c409719d..c87a242f94 100644
--- a/core/modules/node/tests/src/Functional/Views/BulkFormAccessTest.php
+++ b/core/modules/node/tests/src/Functional/Views/BulkFormAccessTest.php
@@ -22,7 +22,7 @@ class BulkFormAccessTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test_views', 'node_access_test'];
+  protected static $modules = ['node_test_views', 'node_access_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/BulkFormTest.php b/core/modules/node/tests/src/Functional/Views/BulkFormTest.php
index eded04530d..da3489e79e 100644
--- a/core/modules/node/tests/src/Functional/Views/BulkFormTest.php
+++ b/core/modules/node/tests/src/Functional/Views/BulkFormTest.php
@@ -19,7 +19,7 @@ class BulkFormTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node_test_views', 'language'];
+  protected static $modules = ['node_test_views', 'language'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/FilterNodeAccessTest.php b/core/modules/node/tests/src/Functional/Views/FilterNodeAccessTest.php
index 7eb7097d9d..83976e422e 100644
--- a/core/modules/node/tests/src/Functional/Views/FilterNodeAccessTest.php
+++ b/core/modules/node/tests/src/Functional/Views/FilterNodeAccessTest.php
@@ -22,7 +22,7 @@ class FilterNodeAccessTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node_access_test'];
+  protected static $modules = ['node_access_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/FrontPageTest.php b/core/modules/node/tests/src/Functional/Views/FrontPageTest.php
index 618119c061..e48f014ab6 100644
--- a/core/modules/node/tests/src/Functional/Views/FrontPageTest.php
+++ b/core/modules/node/tests/src/Functional/Views/FrontPageTest.php
@@ -37,7 +37,7 @@ class FrontPageTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'contextual'];
+  protected static $modules = ['node', 'contextual'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Views/NodeFieldFilterTest.php b/core/modules/node/tests/src/Functional/Views/NodeFieldFilterTest.php
index c2ee2f2763..cdb0816965 100644
--- a/core/modules/node/tests/src/Functional/Views/NodeFieldFilterTest.php
+++ b/core/modules/node/tests/src/Functional/Views/NodeFieldFilterTest.php
@@ -14,7 +14,7 @@ class NodeFieldFilterTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/NodeLanguageTest.php b/core/modules/node/tests/src/Functional/Views/NodeLanguageTest.php
index 31e085213c..d4821f5cfd 100644
--- a/core/modules/node/tests/src/Functional/Views/NodeLanguageTest.php
+++ b/core/modules/node/tests/src/Functional/Views/NodeLanguageTest.php
@@ -19,7 +19,7 @@ class NodeLanguageTest extends NodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'node_test_views'];
+  protected static $modules = ['language', 'node_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/NodeTestBase.php b/core/modules/node/tests/src/Functional/Views/NodeTestBase.php
index b98778c503..f8a6a3c9d6 100644
--- a/core/modules/node/tests/src/Functional/Views/NodeTestBase.php
+++ b/core/modules/node/tests/src/Functional/Views/NodeTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node_test_views'];
+  protected static $modules = ['node_test_views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Functional/Views/PathPluginTest.php b/core/modules/node/tests/src/Functional/Views/PathPluginTest.php
index d8d088d978..b37fdf3f5f 100644
--- a/core/modules/node/tests/src/Functional/Views/PathPluginTest.php
+++ b/core/modules/node/tests/src/Functional/Views/PathPluginTest.php
@@ -16,7 +16,7 @@ class PathPluginTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Functional/Views/RowPluginTest.php b/core/modules/node/tests/src/Functional/Views/RowPluginTest.php
index fdd4d45ad2..5708377f31 100644
--- a/core/modules/node/tests/src/Functional/Views/RowPluginTest.php
+++ b/core/modules/node/tests/src/Functional/Views/RowPluginTest.php
@@ -17,7 +17,7 @@ class RowPluginTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/FunctionalJavascript/NodePreviewLinkTest.php b/core/modules/node/tests/src/FunctionalJavascript/NodePreviewLinkTest.php
index e1c185000f..c3ec8efe48 100644
--- a/core/modules/node/tests/src/FunctionalJavascript/NodePreviewLinkTest.php
+++ b/core/modules/node/tests/src/FunctionalJavascript/NodePreviewLinkTest.php
@@ -15,7 +15,7 @@ class NodePreviewLinkTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'filter'];
+  protected static $modules = ['node', 'filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/FunctionalJavascript/TestSettingSummariesContentType.php b/core/modules/node/tests/src/FunctionalJavascript/TestSettingSummariesContentType.php
index aef0c1e27d..9f74808117 100644
--- a/core/modules/node/tests/src/FunctionalJavascript/TestSettingSummariesContentType.php
+++ b/core/modules/node/tests/src/FunctionalJavascript/TestSettingSummariesContentType.php
@@ -14,7 +14,7 @@ class TestSettingSummariesContentType extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Action/UnpublishByKeywordActionTest.php b/core/modules/node/tests/src/Kernel/Action/UnpublishByKeywordActionTest.php
index 88eb122bb5..f7d4efba89 100644
--- a/core/modules/node/tests/src/Kernel/Action/UnpublishByKeywordActionTest.php
+++ b/core/modules/node/tests/src/Kernel/Action/UnpublishByKeywordActionTest.php
@@ -13,7 +13,7 @@ class UnpublishByKeywordActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['action', 'node', 'system', 'user'];
+  protected static $modules = ['action', 'node', 'system', 'user'];
 
   /**
    * Tests creating an action using the node_unpublish_by_keyword_action plugin.
diff --git a/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php b/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
index d670e6a44c..f7215bc4dd 100644
--- a/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
+++ b/core/modules/node/tests/src/Kernel/Config/NodeImportChangeTest.php
@@ -17,7 +17,7 @@ class NodeImportChangeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field', 'text', 'system', 'node_test_config', 'user'];
+  protected static $modules = ['node', 'field', 'text', 'system', 'node_test_config', 'user'];
 
   /**
    * Set the default field storage backend for fields created during tests.
diff --git a/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php b/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
index 0b27bc2a22..6d368dba12 100644
--- a/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
+++ b/core/modules/node/tests/src/Kernel/Config/NodeImportCreateTest.php
@@ -18,7 +18,7 @@ class NodeImportCreateTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field', 'text', 'system', 'user'];
+  protected static $modules = ['node', 'field', 'text', 'system', 'user'];
 
   /**
    * Set the default field storage backend for fields created during tests.
diff --git a/core/modules/node/tests/src/Kernel/Migrate/MigrateNodeStubTest.php b/core/modules/node/tests/src/Kernel/Migrate/MigrateNodeStubTest.php
index 5b393b196b..d0b66f7606 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/MigrateNodeStubTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/MigrateNodeStubTest.php
@@ -18,7 +18,7 @@ class MigrateNodeStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeBundleSettingsTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeBundleSettingsTest.php
index 34c8dd3ddc..5dee908fa4 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeBundleSettingsTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeBundleSettingsTest.php
@@ -16,7 +16,7 @@ class MigrateNodeBundleSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingPromoteTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingPromoteTest.php
index e7eb008ae7..6dd69f2d0f 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingPromoteTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingPromoteTest.php
@@ -10,7 +10,7 @@
  */
 class MigrateNodeSettingPromoteTest extends MigrateDrupal6TestBase {
 
-  public static $modules = ['node', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStatusTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStatusTest.php
index afd2dc6ed7..d59f63f532 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStatusTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStatusTest.php
@@ -10,7 +10,7 @@
  */
 class MigrateNodeSettingStatusTest extends MigrateDrupal6TestBase {
 
-  public static $modules = ['node', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStickyTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStickyTest.php
index 58eeca33f6..aaf6863511 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStickyTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeSettingStickyTest.php
@@ -10,7 +10,7 @@
  */
 class MigrateNodeSettingStickyTest extends MigrateDrupal6TestBase {
 
-  public static $modules = ['node', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
index 700311c871..192dcec3f2 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTest.php
@@ -19,7 +19,7 @@ class MigrateNodeTest extends MigrateNodeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'menu_ui',
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTypeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTypeTest.php
index f36aebda01..f71116bdde 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/MigrateNodeTypeTest.php
@@ -16,7 +16,7 @@ class MigrateNodeTypeTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d6/NodeTranslationRedirectTest.php b/core/modules/node/tests/src/Kernel/Migrate/d6/NodeTranslationRedirectTest.php
index f3d03166cf..2d9c005c9f 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d6/NodeTranslationRedirectTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d6/NodeTranslationRedirectTest.php
@@ -16,7 +16,7 @@ class NodeTranslationRedirectTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeDeriverTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeDeriverTest.php
index 437126803d..6087e6f493 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeDeriverTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeDeriverTest.php
@@ -14,7 +14,7 @@ class MigrateNodeDeriverTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Test node translation migrations with translation disabled.
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeSettingsTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeSettingsTest.php
index dcae81b8c0..c0f5de85b3 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeSettingsTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeSettingsTest.php
@@ -19,7 +19,7 @@ class MigrateNodeSettingsTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
index da930ec684..da8f4be35b 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
@@ -20,7 +20,7 @@ class MigrateNodeTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'comment',
     'datetime',
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTitleLabelTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTitleLabelTest.php
index 0655631565..ed5239ffee 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTitleLabelTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTitleLabelTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateNodeTitleLabelTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['node', 'text', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTypeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTypeTest.php
index b16cd2550e..130aa9d7be 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTypeTest.php
@@ -20,7 +20,7 @@ class MigrateNodeTypeTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'text', 'filter', 'menu_ui'];
+  protected static $modules = ['node', 'text', 'filter', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Migrate/d7/NodeTranslationRedirectTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/NodeTranslationRedirectTest.php
index 3e148aaf48..52a5683de3 100644
--- a/core/modules/node/tests/src/Kernel/Migrate/d7/NodeTranslationRedirectTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/NodeTranslationRedirectTest.php
@@ -16,7 +16,7 @@ class NodeTranslationRedirectTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessTest.php b/core/modules/node/tests/src/Kernel/NodeAccessTest.php
index 539edcb09b..84a0d52dcd 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessTest.php
@@ -34,7 +34,7 @@ class NodeAccessTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'datetime',
     'user',
diff --git a/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php b/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
index 3dd13496d6..bb60a5c5fd 100644
--- a/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeBodyFieldStorageTest.php
@@ -19,7 +19,7 @@ class NodeBodyFieldStorageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'system', 'field', 'node', 'text', 'filter'];
+  protected static $modules = ['user', 'system', 'field', 'node', 'text', 'filter'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Kernel/NodeConditionTest.php b/core/modules/node/tests/src/Kernel/NodeConditionTest.php
index a30867cb8b..15b704e876 100644
--- a/core/modules/node/tests/src/Kernel/NodeConditionTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeConditionTest.php
@@ -13,7 +13,7 @@
  */
 class NodeConditionTest extends EntityKernelTestBase {
 
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php b/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
index 812731fc61..7794326c3f 100644
--- a/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeFieldAccessTest.php
@@ -19,7 +19,7 @@ class NodeFieldAccessTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Fields that only users with administer nodes permissions can change.
diff --git a/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php b/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
index 7c7bc03348..453ccab7bb 100644
--- a/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeFieldOverridesTest.php
@@ -27,7 +27,7 @@ class NodeFieldOverridesTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'system', 'field', 'node'];
+  protected static $modules = ['user', 'system', 'field', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php b/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
index 420b30661e..f4948b1571 100644
--- a/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeListBuilderTest.php
@@ -15,7 +15,7 @@ class NodeListBuilderTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Kernel/NodeOwnerTest.php b/core/modules/node/tests/src/Kernel/NodeOwnerTest.php
index c12f3115c1..0c00164b4c 100644
--- a/core/modules/node/tests/src/Kernel/NodeOwnerTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeOwnerTest.php
@@ -19,7 +19,7 @@ class NodeOwnerTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'language'];
+  protected static $modules = ['node', 'language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
index dd39b6d26d..50d6aceab2 100644
--- a/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeTokenReplaceTest.php
@@ -22,7 +22,7 @@ class NodeTokenReplaceTest extends TokenReplaceKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'filter'];
+  protected static $modules = ['node', 'filter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/NodeValidationTest.php b/core/modules/node/tests/src/Kernel/NodeValidationTest.php
index e111faeaef..97c598feb1 100644
--- a/core/modules/node/tests/src/Kernel/NodeValidationTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeValidationTest.php
@@ -18,7 +18,7 @@ class NodeValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Set the default field storage backend for fields created during tests.
diff --git a/core/modules/node/tests/src/Kernel/NodeViewBuilderTest.php b/core/modules/node/tests/src/Kernel/NodeViewBuilderTest.php
index d92bd8fd72..95c40d9b6b 100644
--- a/core/modules/node/tests/src/Kernel/NodeViewBuilderTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeViewBuilderTest.php
@@ -19,7 +19,7 @@ class NodeViewBuilderTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * The node storage.
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeByNodeTypeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeByNodeTypeTest.php
index d5a8db09da..d35d6fee30 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeByNodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeByNodeTypeTest.php
@@ -16,7 +16,7 @@ class NodeByNodeTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionByNodeTypeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionByNodeTypeTest.php
index 27e17cc41f..75434abc33 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionByNodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionByNodeTypeTest.php
@@ -16,7 +16,7 @@ class NodeRevisionByNodeTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionTest.php
index fbc28c5ce0..11d63decc4 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeRevisionTest.php
@@ -16,7 +16,7 @@ class NodeRevisionTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTest.php
index 4bc1be0afe..9a78d61da3 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTest.php
@@ -16,7 +16,7 @@ class NodeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTranslationTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTranslationTest.php
index e7de62b07a..95addeb8a0 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTranslationTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTranslationTest.php
@@ -14,7 +14,7 @@ class NodeTranslationTest extends NodeTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTypeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTypeTest.php
index 9d59f43f0b..bd349c6113 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeTypeTest.php
@@ -16,7 +16,7 @@ class NodeTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/ViewModeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/ViewModeTest.php
index 18d941c8a5..e818cbee00 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/ViewModeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/ViewModeTest.php
@@ -16,7 +16,7 @@ class ViewModeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeEntityTranslationTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeEntityTranslationTest.php
index ef33a9624e..8be55b5e84 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeEntityTranslationTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeEntityTranslationTest.php
@@ -16,7 +16,7 @@ class NodeEntityTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTest.php
index 010b90dc03..19cc8d5fbc 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTest.php
@@ -16,7 +16,7 @@ class NodeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTranslationTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTranslationTest.php
index d3229e420c..da73d9123c 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTranslationTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTranslationTest.php
@@ -14,7 +14,7 @@ class NodeTranslationTest extends NodeTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTypeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTypeTest.php
index 5e876b7d4a..45f054110a 100644
--- a/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTypeTest.php
+++ b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTypeTest.php
@@ -16,7 +16,7 @@ class NodeTypeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'migrate_drupal'];
+  protected static $modules = ['node', 'user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/SummaryLengthTest.php b/core/modules/node/tests/src/Kernel/SummaryLengthTest.php
index eecb0d0188..cb3284d605 100644
--- a/core/modules/node/tests/src/Kernel/SummaryLengthTest.php
+++ b/core/modules/node/tests/src/Kernel/SummaryLengthTest.php
@@ -36,7 +36,7 @@ class SummaryLengthTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'datetime',
     'user',
diff --git a/core/modules/node/tests/src/Kernel/Views/ArgumentUidRevisionTest.php b/core/modules/node/tests/src/Kernel/Views/ArgumentUidRevisionTest.php
index b216f40fb2..8ffb8b324d 100644
--- a/core/modules/node/tests/src/Kernel/Views/ArgumentUidRevisionTest.php
+++ b/core/modules/node/tests/src/Kernel/Views/ArgumentUidRevisionTest.php
@@ -19,7 +19,7 @@ class ArgumentUidRevisionTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'field', 'text', 'user', 'node_test_views'];
+  protected static $modules = ['node', 'field', 'text', 'user', 'node_test_views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Views/NidArgumentTest.php b/core/modules/node/tests/src/Kernel/Views/NidArgumentTest.php
index 78ec67b19c..faea6378ac 100644
--- a/core/modules/node/tests/src/Kernel/Views/NidArgumentTest.php
+++ b/core/modules/node/tests/src/Kernel/Views/NidArgumentTest.php
@@ -18,7 +18,7 @@ class NidArgumentTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'field', 'text', 'node_test_config', 'user', 'node_test_views'];
+  protected static $modules = ['node', 'field', 'text', 'node_test_config', 'user', 'node_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/node/tests/src/Kernel/Views/NodeViewsFieldAccessTest.php b/core/modules/node/tests/src/Kernel/Views/NodeViewsFieldAccessTest.php
index 7c68e8899d..4587d6f2e9 100644
--- a/core/modules/node/tests/src/Kernel/Views/NodeViewsFieldAccessTest.php
+++ b/core/modules/node/tests/src/Kernel/Views/NodeViewsFieldAccessTest.php
@@ -17,7 +17,7 @@ class NodeViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'entity_test'];
+  protected static $modules = ['node', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Views/RevisionCreateTimestampTest.php b/core/modules/node/tests/src/Kernel/Views/RevisionCreateTimestampTest.php
index 287bf48395..3c2ffcaa9c 100644
--- a/core/modules/node/tests/src/Kernel/Views/RevisionCreateTimestampTest.php
+++ b/core/modules/node/tests/src/Kernel/Views/RevisionCreateTimestampTest.php
@@ -18,7 +18,7 @@ class RevisionCreateTimestampTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node_test_views', 'node', 'views', 'user'];
+  protected static $modules = ['node_test_views', 'node', 'views', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/tests/src/Kernel/Views/RevisionRelationshipsTest.php b/core/modules/node/tests/src/Kernel/Views/RevisionRelationshipsTest.php
index e47bdd038b..3a021bc774 100644
--- a/core/modules/node/tests/src/Kernel/Views/RevisionRelationshipsTest.php
+++ b/core/modules/node/tests/src/Kernel/Views/RevisionRelationshipsTest.php
@@ -20,7 +20,7 @@ class RevisionRelationshipsTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node' , 'node_test_views'];
+  protected static $modules = ['node' , 'node_test_views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/options/tests/src/Functional/OptionsDynamicValuesTestBase.php b/core/modules/options/tests/src/Functional/OptionsDynamicValuesTestBase.php
index 16c29907c8..728570d4dd 100644
--- a/core/modules/options/tests/src/Functional/OptionsDynamicValuesTestBase.php
+++ b/core/modules/options/tests/src/Functional/OptionsDynamicValuesTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['options', 'entity_test', 'options_test'];
+  protected static $modules = ['options', 'entity_test', 'options_test'];
 
   /**
    * The created entity.
diff --git a/core/modules/options/tests/src/Functional/OptionsFieldUITest.php b/core/modules/options/tests/src/Functional/OptionsFieldUITest.php
index b61748397c..a9ace4dda9 100644
--- a/core/modules/options/tests/src/Functional/OptionsFieldUITest.php
+++ b/core/modules/options/tests/src/Functional/OptionsFieldUITest.php
@@ -18,7 +18,7 @@ class OptionsFieldUITest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'options', 'field_test', 'taxonomy', 'field_ui'];
+  protected static $modules = ['node', 'options', 'field_test', 'taxonomy', 'field_ui'];
 
   /**
    * The name of the created content type.
diff --git a/core/modules/options/tests/src/Functional/OptionsFloatFieldImportTest.php b/core/modules/options/tests/src/Functional/OptionsFloatFieldImportTest.php
index d4d6afff95..5ba1a687c8 100644
--- a/core/modules/options/tests/src/Functional/OptionsFloatFieldImportTest.php
+++ b/core/modules/options/tests/src/Functional/OptionsFloatFieldImportTest.php
@@ -18,7 +18,7 @@ class OptionsFloatFieldImportTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'options', 'field_ui', 'config', 'options_config_install_test'];
+  protected static $modules = ['node', 'options', 'field_ui', 'config', 'options_config_install_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/options/tests/src/Functional/OptionsWidgetsTest.php b/core/modules/options/tests/src/Functional/OptionsWidgetsTest.php
index 5f15ac9cbe..84c338194f 100644
--- a/core/modules/options/tests/src/Functional/OptionsWidgetsTest.php
+++ b/core/modules/options/tests/src/Functional/OptionsWidgetsTest.php
@@ -19,7 +19,7 @@ class OptionsWidgetsTest extends FieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'options', 'entity_test', 'options_test', 'taxonomy', 'field_ui'];
+  protected static $modules = ['node', 'options', 'entity_test', 'options_test', 'taxonomy', 'field_ui'];
 
   /**
    * A field storage with cardinality 1 to use in this test class.
diff --git a/core/modules/options/tests/src/Kernel/OptionsFieldTest.php b/core/modules/options/tests/src/Kernel/OptionsFieldTest.php
index 401d6bc1da..6395e87c68 100644
--- a/core/modules/options/tests/src/Kernel/OptionsFieldTest.php
+++ b/core/modules/options/tests/src/Kernel/OptionsFieldTest.php
@@ -19,7 +19,7 @@ class OptionsFieldTest extends OptionsFieldUnitTestBase {
    *
    * @var array
    */
-  public static $modules = ['options'];
+  protected static $modules = ['options'];
 
   /**
    * Test that allowed values can be updated.
diff --git a/core/modules/options/tests/src/Kernel/OptionsFieldUnitTestBase.php b/core/modules/options/tests/src/Kernel/OptionsFieldUnitTestBase.php
index 9098b818b7..121a59550e 100644
--- a/core/modules/options/tests/src/Kernel/OptionsFieldUnitTestBase.php
+++ b/core/modules/options/tests/src/Kernel/OptionsFieldUnitTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['options'];
+  protected static $modules = ['options'];
 
   /**
    * The field name used in the test.
diff --git a/core/modules/options/tests/src/Kernel/Views/FileViewsDataTest.php b/core/modules/options/tests/src/Kernel/Views/FileViewsDataTest.php
index c5f2902d05..ea35b87ff3 100644
--- a/core/modules/options/tests/src/Kernel/Views/FileViewsDataTest.php
+++ b/core/modules/options/tests/src/Kernel/Views/FileViewsDataTest.php
@@ -19,7 +19,7 @@ class FileViewsDataTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'views', 'entity_test', 'user', 'field'];
+  protected static $modules = ['file', 'views', 'entity_test', 'user', 'field'];
 
   /**
    * Tests views data generated for file field relationship.
diff --git a/core/modules/options/tests/src/Kernel/Views/OptionsTestBase.php b/core/modules/options/tests/src/Kernel/Views/OptionsTestBase.php
index 9f53e63313..4f612b6a5e 100644
--- a/core/modules/options/tests/src/Kernel/Views/OptionsTestBase.php
+++ b/core/modules/options/tests/src/Kernel/Views/OptionsTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['options', 'options_test_views', 'node', 'user', 'field'];
+  protected static $modules = ['options', 'options_test_views', 'node', 'user', 'field'];
 
   /**
    * Stores the nodes used for the different tests.
diff --git a/core/modules/options/tests/src/Kernel/Views/ViewsDataTest.php b/core/modules/options/tests/src/Kernel/Views/ViewsDataTest.php
index d0235986c4..801cd1e190 100644
--- a/core/modules/options/tests/src/Kernel/Views/ViewsDataTest.php
+++ b/core/modules/options/tests/src/Kernel/Views/ViewsDataTest.php
@@ -15,7 +15,7 @@ class ViewsDataTest extends OptionsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['options', 'options_test', 'entity_test', 'views'];
+  protected static $modules = ['options', 'options_test', 'entity_test', 'views'];
 
   /**
    * The field storage.
diff --git a/core/modules/page_cache/tests/src/Functional/PageCacheTest.php b/core/modules/page_cache/tests/src/Functional/PageCacheTest.php
index 3e90d8eb2c..788db446bd 100644
--- a/core/modules/page_cache/tests/src/Functional/PageCacheTest.php
+++ b/core/modules/page_cache/tests/src/Functional/PageCacheTest.php
@@ -27,7 +27,7 @@ class PageCacheTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['test_page_test', 'system_test', 'entity_test'];
+  protected static $modules = ['test_page_test', 'system_test', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/path/src/Tests/PathTestBase.php b/core/modules/path/src/Tests/PathTestBase.php
index 33cf5aba9d..b42349b9c1 100644
--- a/core/modules/path/src/Tests/PathTestBase.php
+++ b/core/modules/path/src/Tests/PathTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathAdminTest.php b/core/modules/path/tests/src/Functional/PathAdminTest.php
index a43a1f8de2..5910aa508e 100644
--- a/core/modules/path/tests/src/Functional/PathAdminTest.php
+++ b/core/modules/path/tests/src/Functional/PathAdminTest.php
@@ -14,7 +14,7 @@ class PathAdminTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['path'];
+  protected static $modules = ['path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathAliasTest.php b/core/modules/path/tests/src/Functional/PathAliasTest.php
index b8ac5968db..7a534d2cdf 100644
--- a/core/modules/path/tests/src/Functional/PathAliasTest.php
+++ b/core/modules/path/tests/src/Functional/PathAliasTest.php
@@ -18,7 +18,7 @@ class PathAliasTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['path'];
+  protected static $modules = ['path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathContentModerationTest.php b/core/modules/path/tests/src/Functional/PathContentModerationTest.php
index 953f1116ba..c6e034af14 100644
--- a/core/modules/path/tests/src/Functional/PathContentModerationTest.php
+++ b/core/modules/path/tests/src/Functional/PathContentModerationTest.php
@@ -21,7 +21,7 @@ class PathContentModerationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'path', 'content_moderation'];
+  protected static $modules = ['node', 'path', 'content_moderation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/path/tests/src/Functional/PathLanguageTest.php b/core/modules/path/tests/src/Functional/PathLanguageTest.php
index 8e41edeaee..2fa6d07903 100644
--- a/core/modules/path/tests/src/Functional/PathLanguageTest.php
+++ b/core/modules/path/tests/src/Functional/PathLanguageTest.php
@@ -14,7 +14,7 @@ class PathLanguageTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'locale', 'locale_test', 'content_translation'];
+  protected static $modules = ['path', 'locale', 'locale_test', 'content_translation'];
 
   /**
    * An user with permissions to administer content types.
diff --git a/core/modules/path/tests/src/Functional/PathLanguageUiTest.php b/core/modules/path/tests/src/Functional/PathLanguageUiTest.php
index c2e3276246..c9d235b617 100644
--- a/core/modules/path/tests/src/Functional/PathLanguageUiTest.php
+++ b/core/modules/path/tests/src/Functional/PathLanguageUiTest.php
@@ -14,7 +14,7 @@ class PathLanguageUiTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'locale', 'locale_test'];
+  protected static $modules = ['path', 'locale', 'locale_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathMediaFormTest.php b/core/modules/path/tests/src/Functional/PathMediaFormTest.php
index 3a96900810..54df43f485 100644
--- a/core/modules/path/tests/src/Functional/PathMediaFormTest.php
+++ b/core/modules/path/tests/src/Functional/PathMediaFormTest.php
@@ -14,7 +14,7 @@ class PathMediaFormTest extends PathTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media', 'media_test_source'];
+  protected static $modules = ['media', 'media_test_source'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/path/tests/src/Functional/PathNodeFormTest.php b/core/modules/path/tests/src/Functional/PathNodeFormTest.php
index 3245b17c59..cda5f0b4e9 100644
--- a/core/modules/path/tests/src/Functional/PathNodeFormTest.php
+++ b/core/modules/path/tests/src/Functional/PathNodeFormTest.php
@@ -14,7 +14,7 @@ class PathNodeFormTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathTaxonomyTermTest.php b/core/modules/path/tests/src/Functional/PathTaxonomyTermTest.php
index 80bedab756..1730d269fa 100644
--- a/core/modules/path/tests/src/Functional/PathTaxonomyTermTest.php
+++ b/core/modules/path/tests/src/Functional/PathTaxonomyTermTest.php
@@ -16,7 +16,7 @@ class PathTaxonomyTermTest extends PathTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Functional/PathTestBase.php b/core/modules/path/tests/src/Functional/PathTestBase.php
index d4b8826d58..e7b9096695 100644
--- a/core/modules/path/tests/src/Functional/PathTestBase.php
+++ b/core/modules/path/tests/src/Functional/PathTestBase.php
@@ -14,7 +14,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Kernel/Migrate/d6/MigrateUrlAliasTest.php b/core/modules/path/tests/src/Kernel/Migrate/d6/MigrateUrlAliasTest.php
index 28f22ecc95..9b708d1b61 100644
--- a/core/modules/path/tests/src/Kernel/Migrate/d6/MigrateUrlAliasTest.php
+++ b/core/modules/path/tests/src/Kernel/Migrate/d6/MigrateUrlAliasTest.php
@@ -16,7 +16,7 @@ class MigrateUrlAliasTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'path',
diff --git a/core/modules/path/tests/src/Kernel/Migrate/d7/MigrateUrlAliasTest.php b/core/modules/path/tests/src/Kernel/Migrate/d7/MigrateUrlAliasTest.php
index b8d92e0c49..367bc594bf 100644
--- a/core/modules/path/tests/src/Kernel/Migrate/d7/MigrateUrlAliasTest.php
+++ b/core/modules/path/tests/src/Kernel/Migrate/d7/MigrateUrlAliasTest.php
@@ -14,7 +14,7 @@ class MigrateUrlAliasTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/path/tests/src/Kernel/PathItemTest.php b/core/modules/path/tests/src/Kernel/PathItemTest.php
index 224a8420b3..9395cc73ac 100644
--- a/core/modules/path/tests/src/Kernel/PathItemTest.php
+++ b/core/modules/path/tests/src/Kernel/PathItemTest.php
@@ -19,7 +19,7 @@ class PathItemTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'node', 'user', 'system', 'language', 'content_translation'];
+  protected static $modules = ['path', 'node', 'user', 'system', 'language', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/path/tests/src/Kernel/PathNoCanonicalLinkTest.php b/core/modules/path/tests/src/Kernel/PathNoCanonicalLinkTest.php
index 773b792f38..2ef03a7b82 100644
--- a/core/modules/path/tests/src/Kernel/PathNoCanonicalLinkTest.php
+++ b/core/modules/path/tests/src/Kernel/PathNoCanonicalLinkTest.php
@@ -18,7 +18,7 @@ class PathNoCanonicalLinkTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'content_translation_test', 'language', 'entity_test', 'user', 'system'];
+  protected static $modules = ['path', 'content_translation_test', 'language', 'entity_test', 'user', 'system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d6/UrlAliasTest.php b/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d6/UrlAliasTest.php
index 1057dffbee..4cfe6d1226 100644
--- a/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d6/UrlAliasTest.php
+++ b/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d6/UrlAliasTest.php
@@ -15,7 +15,7 @@ class UrlAliasTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal', 'path'];
+  protected static $modules = ['migrate_drupal', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d7/UrlAliasTest.php b/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d7/UrlAliasTest.php
index 2fdfd361d6..191b0794d9 100644
--- a/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d7/UrlAliasTest.php
+++ b/core/modules/path/tests/src/Kernel/Plugin/migrate/source/d7/UrlAliasTest.php
@@ -15,7 +15,7 @@ class UrlAliasTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal', 'path'];
+  protected static $modules = ['migrate_drupal', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/quickedit/src/Tests/QuickEditAutocompleteTermTest.php b/core/modules/quickedit/src/Tests/QuickEditAutocompleteTermTest.php
index a1ef6cd2e8..86fa48b9a0 100644
--- a/core/modules/quickedit/src/Tests/QuickEditAutocompleteTermTest.php
+++ b/core/modules/quickedit/src/Tests/QuickEditAutocompleteTermTest.php
@@ -25,7 +25,7 @@ class QuickEditAutocompleteTermTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'taxonomy', 'quickedit'];
+  protected static $modules = ['node', 'taxonomy', 'quickedit'];
 
   /**
    * Stores the node used for the tests.
diff --git a/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php b/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php
index 61af1f52b6..e645059757 100644
--- a/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php
+++ b/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php
@@ -26,7 +26,7 @@ class QuickEditLoadingTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
     'quickedit',
     'filter',
diff --git a/core/modules/quickedit/tests/src/FunctionalJavascript/FieldTest.php b/core/modules/quickedit/tests/src/FunctionalJavascript/FieldTest.php
index 7555220acf..44450d633b 100644
--- a/core/modules/quickedit/tests/src/FunctionalJavascript/FieldTest.php
+++ b/core/modules/quickedit/tests/src/FunctionalJavascript/FieldTest.php
@@ -21,7 +21,7 @@ class FieldTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'ckeditor',
     'contextual',
diff --git a/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php b/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
index cb3f141b06..340e1e41c7 100644
--- a/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
+++ b/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
@@ -21,7 +21,7 @@ class QuickEditIntegrationTest extends QuickEditJavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'editor',
     'ckeditor',
diff --git a/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditJavascriptTestBase.php b/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditJavascriptTestBase.php
index 8c939b3264..77d3f44ed2 100644
--- a/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditJavascriptTestBase.php
+++ b/core/modules/quickedit/tests/src/FunctionalJavascript/QuickEditJavascriptTestBase.php
@@ -13,7 +13,7 @@ class QuickEditJavascriptTestBase extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contextual', 'quickedit', 'toolbar'];
+  protected static $modules = ['contextual', 'quickedit', 'toolbar'];
 
   /**
    * A user with permissions to edit Articles and use Quick Edit.
diff --git a/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php b/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
index 75f3030494..974208a90c 100644
--- a/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
+++ b/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
@@ -18,7 +18,7 @@ class MetadataGeneratorTest extends QuickEditTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['quickedit_test'];
+  protected static $modules = ['quickedit_test'];
 
   /**
    * The manager for editor plugins.
diff --git a/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php b/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
index 8cc2d2f8b6..e5bc63dd84 100644
--- a/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
+++ b/core/modules/quickedit/tests/src/Kernel/QuickEditTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['system', 'entity_test', 'field', 'field_test', 'filter', 'user', 'text', 'quickedit'];
+  protected static $modules = ['system', 'entity_test', 'field', 'field_test', 'filter', 'user', 'text', 'quickedit'];
 
   /**
    * Bag of created fields.
diff --git a/core/modules/rdf/tests/src/Functional/CommentAttributesTest.php b/core/modules/rdf/tests/src/Functional/CommentAttributesTest.php
index 0c194382ba..99a90d1131 100644
--- a/core/modules/rdf/tests/src/Functional/CommentAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/CommentAttributesTest.php
@@ -20,7 +20,7 @@ class CommentAttributesTest extends CommentTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'node', 'comment', 'rdf'];
+  protected static $modules = ['views', 'node', 'comment', 'rdf'];
 
   /**
    * URI of the front page of the Drupal site.
diff --git a/core/modules/rdf/tests/src/Functional/EntityReferenceFieldAttributesTest.php b/core/modules/rdf/tests/src/Functional/EntityReferenceFieldAttributesTest.php
index b91215db5b..2aa26e24d8 100644
--- a/core/modules/rdf/tests/src/Functional/EntityReferenceFieldAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/EntityReferenceFieldAttributesTest.php
@@ -17,7 +17,7 @@ class EntityReferenceFieldAttributesTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'field_test', 'file', 'image'];
+  protected static $modules = ['rdf', 'field_test', 'file', 'image'];
 
   /**
    * The name of the taxonomy term reference field used in the test.
diff --git a/core/modules/rdf/tests/src/Functional/FileFieldAttributesTest.php b/core/modules/rdf/tests/src/Functional/FileFieldAttributesTest.php
index bf567c2615..26d487ee2f 100644
--- a/core/modules/rdf/tests/src/Functional/FileFieldAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/FileFieldAttributesTest.php
@@ -17,7 +17,7 @@ class FileFieldAttributesTest extends FileFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'file'];
+  protected static $modules = ['rdf', 'file'];
 
   /**
    * The name of the file field used in the test.
diff --git a/core/modules/rdf/tests/src/Functional/GetRdfNamespacesTest.php b/core/modules/rdf/tests/src/Functional/GetRdfNamespacesTest.php
index 0b162a4a90..1279455011 100644
--- a/core/modules/rdf/tests/src/Functional/GetRdfNamespacesTest.php
+++ b/core/modules/rdf/tests/src/Functional/GetRdfNamespacesTest.php
@@ -16,7 +16,7 @@ class GetRdfNamespacesTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'rdf_test_namespaces'];
+  protected static $modules = ['rdf', 'rdf_test_namespaces'];
 
   /**
    * Tests getting RDF namespaces.
diff --git a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonAnonTest.php b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonAnonTest.php
index 2d241e9967..7ae23e08fc 100644
--- a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonAnonTest.php
+++ b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class RdfMappingHalJsonAnonTest extends RdfMappingResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonBasicAuthTest.php b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonBasicAuthTest.php
index 346ad229e0..1c7b93496a 100644
--- a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonBasicAuthTest.php
+++ b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class RdfMappingHalJsonBasicAuthTest extends RdfMappingResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonCookieTest.php b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonCookieTest.php
index ff90d902a1..01519357c0 100644
--- a/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonCookieTest.php
+++ b/core/modules/rdf/tests/src/Functional/Hal/RdfMappingHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class RdfMappingHalJsonCookieTest extends RdfMappingResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/ImageFieldAttributesTest.php b/core/modules/rdf/tests/src/Functional/ImageFieldAttributesTest.php
index e5707591f7..9514b12438 100644
--- a/core/modules/rdf/tests/src/Functional/ImageFieldAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/ImageFieldAttributesTest.php
@@ -24,7 +24,7 @@ class ImageFieldAttributesTest extends ImageFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'image'];
+  protected static $modules = ['rdf', 'image'];
 
   /**
    * The name of the image field used in the test.
diff --git a/core/modules/rdf/tests/src/Functional/NodeAttributesTest.php b/core/modules/rdf/tests/src/Functional/NodeAttributesTest.php
index 2e5675fe6a..f74c91b82e 100644
--- a/core/modules/rdf/tests/src/Functional/NodeAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/NodeAttributesTest.php
@@ -16,7 +16,7 @@ class NodeAttributesTest extends NodeTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf'];
+  protected static $modules = ['rdf'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingJsonBasicAuthTest.php b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingJsonBasicAuthTest.php
index 9537336780..832b086ffd 100644
--- a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingJsonBasicAuthTest.php
+++ b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class RdfMappingJsonBasicAuthTest extends RdfMappingResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingResourceTestBase.php b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingResourceTestBase.php
index ffe5bd4fda..bd528aaae7 100644
--- a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingResourceTestBase.php
+++ b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'rdf'];
+  protected static $modules = ['node', 'rdf'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingXmlBasicAuthTest.php b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingXmlBasicAuthTest.php
index 9cf6b97d51..1940ac1eb4 100644
--- a/core/modules/rdf/tests/src/Functional/Rest/RdfMappingXmlBasicAuthTest.php
+++ b/core/modules/rdf/tests/src/Functional/Rest/RdfMappingXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class RdfMappingXmlBasicAuthTest extends RdfMappingResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Functional/TaxonomyAttributesTest.php b/core/modules/rdf/tests/src/Functional/TaxonomyAttributesTest.php
index 346ffb7eb9..bd9c187071 100644
--- a/core/modules/rdf/tests/src/Functional/TaxonomyAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/TaxonomyAttributesTest.php
@@ -16,7 +16,7 @@ class TaxonomyAttributesTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'views'];
+  protected static $modules = ['rdf', 'views'];
 
   /**
    * Vocabulary created for testing purposes.
diff --git a/core/modules/rdf/tests/src/Functional/UserAttributesTest.php b/core/modules/rdf/tests/src/Functional/UserAttributesTest.php
index fddd440894..0a74cb8049 100644
--- a/core/modules/rdf/tests/src/Functional/UserAttributesTest.php
+++ b/core/modules/rdf/tests/src/Functional/UserAttributesTest.php
@@ -16,7 +16,7 @@ class UserAttributesTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'node'];
+  protected static $modules = ['rdf', 'node'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/CrudTest.php b/core/modules/rdf/tests/src/Kernel/CrudTest.php
index f8292a38b7..12a5c3dd91 100644
--- a/core/modules/rdf/tests/src/Kernel/CrudTest.php
+++ b/core/modules/rdf/tests/src/Kernel/CrudTest.php
@@ -16,7 +16,7 @@ class CrudTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'rdf', 'system'];
+  protected static $modules = ['entity_test', 'rdf', 'system'];
 
   /**
    * @var string
diff --git a/core/modules/rdf/tests/src/Kernel/Field/DateTimeFieldRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/DateTimeFieldRdfaTest.php
index fc78691b96..d3d7716c06 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/DateTimeFieldRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/DateTimeFieldRdfaTest.php
@@ -26,7 +26,7 @@ class DateTimeFieldRdfaTest extends FieldRdfaTestBase {
   /**
   * {@inheritdoc}
   */
-  public static $modules = ['datetime'];
+  protected static $modules = ['datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Field/EmailFieldRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/EmailFieldRdfaTest.php
index 85ae888103..91696e778d 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/EmailFieldRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/EmailFieldRdfaTest.php
@@ -19,7 +19,7 @@ class EmailFieldRdfaTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['text'];
+  protected static $modules = ['text'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Field/EntityReferenceRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/EntityReferenceRdfaTest.php
index 9312fbc929..e61b5ba3a6 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/EntityReferenceRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/EntityReferenceRdfaTest.php
@@ -44,7 +44,7 @@ class EntityReferenceRdfaTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['text', 'filter'];
+  protected static $modules = ['text', 'filter'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaDatatypeCallbackTest.php b/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaDatatypeCallbackTest.php
index 81d3a40610..18748b513b 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaDatatypeCallbackTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaDatatypeCallbackTest.php
@@ -19,7 +19,7 @@ class FieldRdfaDatatypeCallbackTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['text', 'filter', 'rdf_test'];
+  protected static $modules = ['text', 'filter', 'rdf_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaTestBase.php b/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaTestBase.php
index 82ea9efdcc..5568f8357b 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaTestBase.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/FieldRdfaTestBase.php
@@ -48,7 +48,7 @@
    *
    * @var array
    */
-  public static $modules = ['rdf'];
+  protected static $modules = ['rdf'];
 
   /**
    * @var string
diff --git a/core/modules/rdf/tests/src/Kernel/Field/LinkFieldRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/LinkFieldRdfaTest.php
index aac9b75591..d3904979b6 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/LinkFieldRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/LinkFieldRdfaTest.php
@@ -19,7 +19,7 @@ class LinkFieldRdfaTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['link', 'text'];
+  protected static $modules = ['link', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rdf/tests/src/Kernel/Field/TelephoneFieldRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/TelephoneFieldRdfaTest.php
index d705b2106d..d28a319ea3 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/TelephoneFieldRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/TelephoneFieldRdfaTest.php
@@ -26,7 +26,7 @@ class TelephoneFieldRdfaTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['telephone', 'text'];
+  protected static $modules = ['telephone', 'text'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Field/TextFieldRdfaTest.php b/core/modules/rdf/tests/src/Kernel/Field/TextFieldRdfaTest.php
index 48bc5b8f6b..34ad8cc59c 100644
--- a/core/modules/rdf/tests/src/Kernel/Field/TextFieldRdfaTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Field/TextFieldRdfaTest.php
@@ -33,7 +33,7 @@ class TextFieldRdfaTest extends FieldRdfaTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['text', 'filter'];
+  protected static $modules = ['text', 'filter'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/rdf/tests/src/Kernel/Migrate/d7/MigrateRdfMappingTest.php b/core/modules/rdf/tests/src/Kernel/Migrate/d7/MigrateRdfMappingTest.php
index c61a7c4039..ac33f687ca 100644
--- a/core/modules/rdf/tests/src/Kernel/Migrate/d7/MigrateRdfMappingTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Migrate/d7/MigrateRdfMappingTest.php
@@ -15,7 +15,7 @@ class MigrateRdfMappingTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_ui',
     'node',
     'rdf',
diff --git a/core/modules/rdf/tests/src/Kernel/Plugin/migrate/source/d7/RdfMappingTest.php b/core/modules/rdf/tests/src/Kernel/Plugin/migrate/source/d7/RdfMappingTest.php
index 82b0497d9b..84a2e3b43c 100644
--- a/core/modules/rdf/tests/src/Kernel/Plugin/migrate/source/d7/RdfMappingTest.php
+++ b/core/modules/rdf/tests/src/Kernel/Plugin/migrate/source/d7/RdfMappingTest.php
@@ -16,7 +16,7 @@ class RdfMappingTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'migrate_drupal',
     'node',
diff --git a/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php b/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
index 4023ef26b2..519d10b200 100644
--- a/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
+++ b/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
@@ -16,7 +16,7 @@ class RdfaAttributesTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf'];
+  protected static $modules = ['rdf'];
 
   /**
    * Test attribute creation for mappings which use 'property'.
diff --git a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php
index 3828ab0d75..1a563914c8 100644
--- a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php
+++ b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php
@@ -31,7 +31,7 @@ class ResponsiveImageFieldDisplayTest extends ImageFieldTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_ui', 'responsive_image', 'responsive_image_test_module'];
+  protected static $modules = ['field_ui', 'responsive_image', 'responsive_image_test_module'];
 
   /**
    * Drupal\simpletest\WebTestBase\setUp().
diff --git a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUiTest.php b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUiTest.php
index 2069f61368..a8a8b6f04b 100644
--- a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUiTest.php
+++ b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUiTest.php
@@ -20,7 +20,7 @@ class ResponsiveImageFieldUiTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'image', 'responsive_image', 'responsive_image_test_module', 'block'];
+  protected static $modules = ['node', 'field_ui', 'image', 'responsive_image', 'responsive_image_test_module', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonAnonTest.php b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonAnonTest.php
index 50dc1970df..60be0741d5 100644
--- a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonAnonTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ResponsiveImageStyleHalJsonAnonTest extends ResponsiveImageStyleResourceTe
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonBasicAuthTest.php b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonBasicAuthTest.php
index 1f45a2d743..8c991cd0b8 100644
--- a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonBasicAuthTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ResponsiveImageStyleHalJsonBasicAuthTest extends ResponsiveImageStyleResou
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonCookieTest.php b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonCookieTest.php
index 85d95431f5..ea4955f6ea 100644
--- a/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonCookieTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/Hal/ResponsiveImageStyleHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ResponsiveImageStyleHalJsonCookieTest extends ResponsiveImageStyleResource
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php b/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php
index ce9050e273..04a5df32c1 100644
--- a/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php
+++ b/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php
@@ -16,7 +16,7 @@ class ResponsiveImageAdminUITest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['responsive_image', 'responsive_image_test_module'];
+  protected static $modules = ['responsive_image', 'responsive_image_test_module'];
 
   /**
    * Drupal\simpletest\WebTestBase\setUp().
diff --git a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonBasicAuthTest.php b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonBasicAuthTest.php
index b3c9127da4..478a149224 100644
--- a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonBasicAuthTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ResponsiveImageStyleJsonBasicAuthTest extends ResponsiveImageStyleResource
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleResourceTestBase.php b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleResourceTestBase.php
index dbef272db2..cabe13a3e7 100644
--- a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleResourceTestBase.php
+++ b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['responsive_image'];
+  protected static $modules = ['responsive_image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlBasicAuthTest.php b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlBasicAuthTest.php
index e850e99d57..110c04ddcd 100644
--- a/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlBasicAuthTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/Rest/ResponsiveImageStyleXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ResponsiveImageStyleXmlBasicAuthTest extends ResponsiveImageStyleResourceT
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/responsive_image/tests/src/Functional/ViewsIntegrationTest.php b/core/modules/responsive_image/tests/src/Functional/ViewsIntegrationTest.php
index 33f19a5be5..2b4f4d3de0 100644
--- a/core/modules/responsive_image/tests/src/Functional/ViewsIntegrationTest.php
+++ b/core/modules/responsive_image/tests/src/Functional/ViewsIntegrationTest.php
@@ -22,7 +22,7 @@ class ViewsIntegrationTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'views',
     'views_ui',
     'responsive_image',
diff --git a/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php b/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php
index d48129122b..00641c646b 100644
--- a/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php
+++ b/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php
@@ -18,7 +18,7 @@ class ResponsiveImageIntegrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['responsive_image', 'field', 'image', 'file', 'entity_test', 'breakpoint', 'responsive_image_test_module'];
+  protected static $modules = ['responsive_image', 'field', 'image', 'file', 'entity_test', 'breakpoint', 'responsive_image_test_module'];
 
   /**
    * Tests integration with entity view display.
diff --git a/core/modules/rest/src/Tests/RESTTestBase.php b/core/modules/rest/src/Tests/RESTTestBase.php
index 66be4b29ea..5aba91d651 100644
--- a/core/modules/rest/src/Tests/RESTTestBase.php
+++ b/core/modules/rest/src/Tests/RESTTestBase.php
@@ -65,7 +65,7 @@
    *
    * @var array
    */
-  public static $modules = ['rest', 'entity_test'];
+  protected static $modules = ['rest', 'entity_test'];
 
   /**
    * The last response.
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
index 5e0d4e5176..4d870c26a2 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
@@ -155,7 +155,7 @@
    *
    * @var array
    */
-  public static $modules = ['rest_test', 'text'];
+  protected static $modules = ['rest_test', 'text'];
 
   /**
    * Provides an entity resource.
diff --git a/core/modules/rest/tests/src/Functional/FileUploadResourceTestBase.php b/core/modules/rest/tests/src/Functional/FileUploadResourceTestBase.php
index 42c7b2c50a..49a0156bdb 100644
--- a/core/modules/rest/tests/src/Functional/FileUploadResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/FileUploadResourceTestBase.php
@@ -25,7 +25,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest_test', 'entity_test', 'file'];
+  protected static $modules = ['rest_test', 'entity_test', 'file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonAnonTest.php b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonAnonTest.php
index 72ccd45e93..9f6a0d445c 100644
--- a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonAnonTest.php
+++ b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class RestResourceConfigHalJsonAnonTest extends RestResourceConfigResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonBasicAuthTest.php
index e5e9a7efbb..70c1680a74 100644
--- a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class RestResourceConfigHalJsonBasicAuthTest extends RestResourceConfigResourceT
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonCookieTest.php b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonCookieTest.php
index 606d3fd641..a1b16d254d 100644
--- a/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonCookieTest.php
+++ b/core/modules/rest/tests/src/Functional/Hal/RestResourceConfigHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class RestResourceConfigHalJsonCookieTest extends RestResourceConfigResourceTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/ResourceTest.php b/core/modules/rest/tests/src/Functional/ResourceTest.php
index d04b990e60..6532ba4a1c 100644
--- a/core/modules/rest/tests/src/Functional/ResourceTest.php
+++ b/core/modules/rest/tests/src/Functional/ResourceTest.php
@@ -23,7 +23,7 @@ class ResourceTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal', 'rest', 'entity_test', 'rest_test'];
+  protected static $modules = ['hal', 'rest', 'entity_test', 'rest_test'];
 
   /**
    * The entity.
diff --git a/core/modules/rest/tests/src/Functional/ResourceTestBase.php b/core/modules/rest/tests/src/Functional/ResourceTestBase.php
index d7ca1e34f3..e0bd2a2ac3 100644
--- a/core/modules/rest/tests/src/Functional/ResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/ResourceTestBase.php
@@ -93,7 +93,7 @@
    *
    * @var array
    */
-  public static $modules = ['rest'];
+  protected static $modules = ['rest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigJsonBasicAuthTest.php
index 8ac84636ec..a5fb61c273 100644
--- a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class RestResourceConfigJsonBasicAuthTest extends RestResourceConfigResourceTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigResourceTestBase.php b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigResourceTestBase.php
index a0b0b2e428..2fdb03d81e 100644
--- a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['dblog'];
+  protected static $modules = ['dblog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigXmlBasicAuthTest.php b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigXmlBasicAuthTest.php
index c5034b4ee5..3d2ffe4ba6 100644
--- a/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigXmlBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/Rest/RestResourceConfigXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class RestResourceConfigXmlBasicAuthTest extends RestResourceConfigResourceTestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Views/ExcludedFieldTokenTest.php b/core/modules/rest/tests/src/Functional/Views/ExcludedFieldTokenTest.php
index cf9913d85a..5eef6fa8fb 100644
--- a/core/modules/rest/tests/src/Functional/Views/ExcludedFieldTokenTest.php
+++ b/core/modules/rest/tests/src/Functional/Views/ExcludedFieldTokenTest.php
@@ -33,7 +33,7 @@ class ExcludedFieldTokenTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'rest_test_views',
     'node',
diff --git a/core/modules/rest/tests/src/Functional/Views/RestExportAuthTest.php b/core/modules/rest/tests/src/Functional/Views/RestExportAuthTest.php
index 24546089cd..476bfcf349 100644
--- a/core/modules/rest/tests/src/Functional/Views/RestExportAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/Views/RestExportAuthTest.php
@@ -15,7 +15,7 @@ class RestExportAuthTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest', 'views_ui', 'basic_auth'];
+  protected static $modules = ['rest', 'views_ui', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/Views/StyleSerializerTest.php b/core/modules/rest/tests/src/Functional/Views/StyleSerializerTest.php
index b60eb0c3f2..249cfd104d 100644
--- a/core/modules/rest/tests/src/Functional/Views/StyleSerializerTest.php
+++ b/core/modules/rest/tests/src/Functional/Views/StyleSerializerTest.php
@@ -36,7 +36,7 @@ class StyleSerializerTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'entity_test', 'hal', 'rest_test_views', 'node', 'text', 'field', 'language', 'basic_auth'];
+  protected static $modules = ['views_ui', 'entity_test', 'hal', 'rest_test_views', 'node', 'text', 'field', 'language', 'basic_auth'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/rest/tests/src/Kernel/Entity/ConfigDependenciesTest.php b/core/modules/rest/tests/src/Kernel/Entity/ConfigDependenciesTest.php
index 500f375ef9..ca0bac7221 100644
--- a/core/modules/rest/tests/src/Kernel/Entity/ConfigDependenciesTest.php
+++ b/core/modules/rest/tests/src/Kernel/Entity/ConfigDependenciesTest.php
@@ -17,7 +17,7 @@ class ConfigDependenciesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest', 'entity_test', 'serialization'];
+  protected static $modules = ['rest', 'entity_test', 'serialization'];
 
   /**
    * @covers ::calculateDependencies
diff --git a/core/modules/rest/tests/src/Kernel/Entity/RestResourceConfigTest.php b/core/modules/rest/tests/src/Kernel/Entity/RestResourceConfigTest.php
index 89e9b1dec5..585743307e 100644
--- a/core/modules/rest/tests/src/Kernel/Entity/RestResourceConfigTest.php
+++ b/core/modules/rest/tests/src/Kernel/Entity/RestResourceConfigTest.php
@@ -16,7 +16,7 @@ class RestResourceConfigTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest', 'entity_test', 'serialization', 'basic_auth', 'user', 'hal'];
+  protected static $modules = ['rest', 'entity_test', 'serialization', 'basic_auth', 'user', 'hal'];
 
   /**
    * @covers ::calculateDependencies
diff --git a/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php b/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
index a791838f9f..30ba59ea8c 100644
--- a/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
+++ b/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
@@ -27,7 +27,7 @@ class RequestHandlerTest extends KernelTestBase {
    */
   protected $requestHandler;
 
-  public static $modules = ['serialization', 'rest'];
+  protected static $modules = ['serialization', 'rest'];
 
   /**
    * The entity storage.
diff --git a/core/modules/rest/tests/src/Kernel/Views/RestExportAuthTest.php b/core/modules/rest/tests/src/Kernel/Views/RestExportAuthTest.php
index 6570706f77..99e8f824a6 100644
--- a/core/modules/rest/tests/src/Kernel/Views/RestExportAuthTest.php
+++ b/core/modules/rest/tests/src/Kernel/Views/RestExportAuthTest.php
@@ -16,7 +16,7 @@ class RestExportAuthTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'rest',
     'views_ui',
diff --git a/core/modules/rest/tests/src/Kernel/Views/RestExportTest.php b/core/modules/rest/tests/src/Kernel/Views/RestExportTest.php
index f3a8f04f52..04c708cacf 100644
--- a/core/modules/rest/tests/src/Kernel/Views/RestExportTest.php
+++ b/core/modules/rest/tests/src/Kernel/Views/RestExportTest.php
@@ -24,7 +24,7 @@ class RestExportTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest_test_views', 'serialization', 'rest', 'entity_test'];
+  protected static $modules = ['rest_test_views', 'serialization', 'rest', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Kernel/Views/StyleSerializerKernelTest.php b/core/modules/rest/tests/src/Kernel/Views/StyleSerializerKernelTest.php
index 829d08bb18..029b523895 100644
--- a/core/modules/rest/tests/src/Kernel/Views/StyleSerializerKernelTest.php
+++ b/core/modules/rest/tests/src/Kernel/Views/StyleSerializerKernelTest.php
@@ -20,7 +20,7 @@ class StyleSerializerKernelTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['rest_test_views', 'serialization', 'rest'];
+  protected static $modules = ['rest_test_views', 'serialization', 'rest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/src/Tests/SearchTestBase.php b/core/modules/search/src/Tests/SearchTestBase.php
index 5d5d0b4b72..98e40acbe6 100644
--- a/core/modules/search/src/Tests/SearchTestBase.php
+++ b/core/modules/search/src/Tests/SearchTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'search', 'dblog'];
+  protected static $modules = ['node', 'search', 'dblog'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonAnonTest.php b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonAnonTest.php
index cd0079803c..75cafa2814 100644
--- a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonAnonTest.php
+++ b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class SearchPageHalJsonAnonTest extends SearchPageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonBasicAuthTest.php b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonBasicAuthTest.php
index d1ff293ba3..feda6cf7f6 100644
--- a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonBasicAuthTest.php
+++ b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class SearchPageHalJsonBasicAuthTest extends SearchPageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonCookieTest.php b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonCookieTest.php
index a09fa5f9b1..1ee7c97773 100644
--- a/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonCookieTest.php
+++ b/core/modules/search/tests/src/Functional/Hal/SearchPageHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class SearchPageHalJsonCookieTest extends SearchPageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/Rest/SearchPageJsonBasicAuthTest.php b/core/modules/search/tests/src/Functional/Rest/SearchPageJsonBasicAuthTest.php
index f311ce9b4d..643309f892 100644
--- a/core/modules/search/tests/src/Functional/Rest/SearchPageJsonBasicAuthTest.php
+++ b/core/modules/search/tests/src/Functional/Rest/SearchPageJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class SearchPageJsonBasicAuthTest extends SearchPageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/Rest/SearchPageResourceTestBase.php b/core/modules/search/tests/src/Functional/Rest/SearchPageResourceTestBase.php
index e711a34799..d03bdab91e 100644
--- a/core/modules/search/tests/src/Functional/Rest/SearchPageResourceTestBase.php
+++ b/core/modules/search/tests/src/Functional/Rest/SearchPageResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'search'];
+  protected static $modules = ['node', 'search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/Rest/SearchPageXmlBasicAuthTest.php b/core/modules/search/tests/src/Functional/Rest/SearchPageXmlBasicAuthTest.php
index 7a2c3c8804..874b8ac497 100644
--- a/core/modules/search/tests/src/Functional/Rest/SearchPageXmlBasicAuthTest.php
+++ b/core/modules/search/tests/src/Functional/Rest/SearchPageXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class SearchPageXmlBasicAuthTest extends SearchPageResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Functional/SearchTestBase.php b/core/modules/search/tests/src/Functional/SearchTestBase.php
index fe6ac7132e..8916d45092 100644
--- a/core/modules/search/tests/src/Functional/SearchTestBase.php
+++ b/core/modules/search/tests/src/Functional/SearchTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'search', 'dblog'];
+  protected static $modules = ['node', 'search', 'dblog'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchPageTest.php b/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchPageTest.php
index a70114a6a9..9ca8a9792d 100644
--- a/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchPageTest.php
+++ b/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchPageTest.php
@@ -16,7 +16,7 @@ class MigrateSearchPageTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['search'];
+  protected static $modules = ['search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchSettingsTest.php b/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchSettingsTest.php
index d28bbd824e..625a69a1c6 100644
--- a/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchSettingsTest.php
+++ b/core/modules/search/tests/src/Kernel/Migrate/d6/MigrateSearchSettingsTest.php
@@ -17,7 +17,7 @@ class MigrateSearchSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['search'];
+  protected static $modules = ['search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchPageTest.php b/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchPageTest.php
index 86d3b22009..fda72cf4c4 100644
--- a/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchPageTest.php
+++ b/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchPageTest.php
@@ -18,7 +18,7 @@ class MigrateSearchPageTest extends MigrateDrupal7TestBase {
    *
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'search'];
+  protected static $modules = ['node', 'search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchSettingsTest.php b/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchSettingsTest.php
index 2306ce7370..47f584a132 100644
--- a/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchSettingsTest.php
+++ b/core/modules/search/tests/src/Kernel/Migrate/d7/MigrateSearchSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateSearchSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['search'];
+  protected static $modules = ['search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/tests/src/Kernel/SearchExcerptTest.php b/core/modules/search/tests/src/Kernel/SearchExcerptTest.php
index e10075d09a..035bf2dc31 100644
--- a/core/modules/search/tests/src/Kernel/SearchExcerptTest.php
+++ b/core/modules/search/tests/src/Kernel/SearchExcerptTest.php
@@ -16,7 +16,7 @@ class SearchExcerptTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['search', 'search_langcode_test'];
+  protected static $modules = ['search', 'search_langcode_test'];
 
   /**
    * Tests search_excerpt() with several simulated search keywords.
diff --git a/core/modules/search/tests/src/Kernel/SearchMatchTest.php b/core/modules/search/tests/src/Kernel/SearchMatchTest.php
index e9d2ac8bca..134a74e33b 100644
--- a/core/modules/search/tests/src/Kernel/SearchMatchTest.php
+++ b/core/modules/search/tests/src/Kernel/SearchMatchTest.php
@@ -23,7 +23,7 @@ class SearchMatchTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['search'];
+  protected static $modules = ['search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/serialization/tests/src/Kernel/EntityResolverTest.php b/core/modules/serialization/tests/src/Kernel/EntityResolverTest.php
index 38af46e994..4332d95c63 100644
--- a/core/modules/serialization/tests/src/Kernel/EntityResolverTest.php
+++ b/core/modules/serialization/tests/src/Kernel/EntityResolverTest.php
@@ -19,7 +19,7 @@ class EntityResolverTest extends NormalizerTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal', 'rest'];
+  protected static $modules = ['hal', 'rest'];
 
   /**
    * The format being tested.
diff --git a/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php b/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
index ef5362a0ed..bec8837677 100644
--- a/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
@@ -22,7 +22,7 @@ class EntitySerializationTest extends NormalizerTestBase {
    *
    * @var array
    */
-  public static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user', 'entity_serialization_test'];
+  protected static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user', 'entity_serialization_test'];
 
   /**
    * The test values.
diff --git a/core/modules/serialization/tests/src/Kernel/FieldItemSerializationTest.php b/core/modules/serialization/tests/src/Kernel/FieldItemSerializationTest.php
index 403f41ab2b..91fd59fce3 100644
--- a/core/modules/serialization/tests/src/Kernel/FieldItemSerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/FieldItemSerializationTest.php
@@ -17,7 +17,7 @@ class FieldItemSerializationTest extends NormalizerTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user', 'field_normalization_test'];
+  protected static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user', 'field_normalization_test'];
 
   /**
    * The class name of the test class.
diff --git a/core/modules/serialization/tests/src/Kernel/MapDataNormalizerTest.php b/core/modules/serialization/tests/src/Kernel/MapDataNormalizerTest.php
index 32dc082652..1b6b9275db 100644
--- a/core/modules/serialization/tests/src/Kernel/MapDataNormalizerTest.php
+++ b/core/modules/serialization/tests/src/Kernel/MapDataNormalizerTest.php
@@ -14,7 +14,7 @@ class MapDataNormalizerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'serialization'];
+  protected static $modules = ['system', 'serialization'];
 
   /**
    * The serializer service.
diff --git a/core/modules/serialization/tests/src/Kernel/NormalizerTestBase.php b/core/modules/serialization/tests/src/Kernel/NormalizerTestBase.php
index 25299b16f0..9db09bbef9 100644
--- a/core/modules/serialization/tests/src/Kernel/NormalizerTestBase.php
+++ b/core/modules/serialization/tests/src/Kernel/NormalizerTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user'];
+  protected static $modules = ['serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/serialization/tests/src/Kernel/SerializationTest.php b/core/modules/serialization/tests/src/Kernel/SerializationTest.php
index a7ad145e65..b0b6a33f32 100644
--- a/core/modules/serialization/tests/src/Kernel/SerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/SerializationTest.php
@@ -17,7 +17,7 @@ class SerializationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['serialization', 'serialization_test'];
+  protected static $modules = ['serialization', 'serialization_test'];
 
   /**
    * The serializer service to test.
diff --git a/core/modules/settings_tray/tests/src/Functional/BcRoutesTest.php b/core/modules/settings_tray/tests/src/Functional/BcRoutesTest.php
index 6750b1c6c0..77dc9f9998 100644
--- a/core/modules/settings_tray/tests/src/Functional/BcRoutesTest.php
+++ b/core/modules/settings_tray/tests/src/Functional/BcRoutesTest.php
@@ -16,7 +16,7 @@ class BcRoutesTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'settings_tray',
   ];
 
diff --git a/core/modules/settings_tray/tests/src/Functional/SettingsTrayTest.php b/core/modules/settings_tray/tests/src/Functional/SettingsTrayTest.php
index aec0392de1..e9fadc8b7b 100644
--- a/core/modules/settings_tray/tests/src/Functional/SettingsTrayTest.php
+++ b/core/modules/settings_tray/tests/src/Functional/SettingsTrayTest.php
@@ -15,7 +15,7 @@ class SettingsTrayTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'settings_tray',
     'settings_tray_test',
   ];
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/ConfigAccessTest.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/ConfigAccessTest.php
index 6b15be9425..86ec1e2000 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/ConfigAccessTest.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/ConfigAccessTest.php
@@ -15,7 +15,7 @@ class ConfigAccessTest extends SettingsTrayTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_link_content',
     'menu_ui',
   ];
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/OverriddenConfigurationTest.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/OverriddenConfigurationTest.php
index 97cd4db18f..41a40b4549 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/OverriddenConfigurationTest.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/OverriddenConfigurationTest.php
@@ -16,7 +16,7 @@ class OverriddenConfigurationTest extends SettingsTrayTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'settings_tray_override_test',
     'menu_ui',
     'menu_link_content',
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
index 6f623cb1bc..15f3a7705c 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/QuickEditIntegrationTest.php
@@ -16,7 +16,7 @@ class QuickEditIntegrationTest extends SettingsTrayTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'block_content',
     'quickedit',
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
index 0e6b9d6251..0704459608 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
@@ -16,7 +16,7 @@ class SettingsTrayBlockFormTest extends SettingsTrayTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'search',
     'settings_tray_test',
diff --git a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
index 2017accd88..63692e954b 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php
@@ -16,7 +16,7 @@ class SettingsTrayTestBase extends OffCanvasTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'settings_tray',
     // Add test module to override CSS pointer-events properties because they
     // cause test failures.
diff --git a/core/modules/shortcut/src/Tests/ShortcutTestBase.php b/core/modules/shortcut/src/Tests/ShortcutTestBase.php
index 584a6154c3..ddf192e197 100644
--- a/core/modules/shortcut/src/Tests/ShortcutTestBase.php
+++ b/core/modules/shortcut/src/Tests/ShortcutTestBase.php
@@ -24,7 +24,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'toolbar', 'shortcut'];
+  protected static $modules = ['node', 'toolbar', 'shortcut'];
 
   /**
    * User with permission to administer shortcuts.
diff --git a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonAnonTest.php b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonAnonTest.php
index ba6c8a798d..66b0f0e478 100644
--- a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonAnonTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class ShortcutHalJsonAnonTest extends ShortcutResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonBasicAuthTest.php
index 784c3ebc44..abf34338a8 100644
--- a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ShortcutHalJsonBasicAuthTest extends ShortcutHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonAnonTest.php b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonAnonTest.php
index b3faae7fba..771707cd30 100644
--- a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonAnonTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ShortcutSetHalJsonAnonTest extends ShortcutSetResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonBasicAuthTest.php
index d3a7057411..ae125dc703 100644
--- a/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Hal/ShortcutSetHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ShortcutSetHalJsonBasicAuthTest extends ShortcutSetHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutJsonBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutJsonBasicAuthTest.php
index e0859e3aa3..b9a2c342c6 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutJsonBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ShortcutJsonBasicAuthTest extends ShortcutResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutResourceTestBase.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutResourceTestBase.php
index 1f588a2500..fa1e4fa491 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutResourceTestBase.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'shortcut'];
+  protected static $modules = ['comment', 'shortcut'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetJsonBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetJsonBasicAuthTest.php
index 6ddaf54b0d..15da60e164 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetJsonBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ShortcutSetJsonBasicAuthTest extends ShortcutSetResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetResourceTestBase.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetResourceTestBase.php
index b25f028d1c..8a1def5ca6 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetResourceTestBase.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut'];
+  protected static $modules = ['shortcut'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetXmlBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetXmlBasicAuthTest.php
index 50c6e71c23..0ffe67c115 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetXmlBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutSetXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ShortcutSetXmlBasicAuthTest extends ShortcutSetResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutXmlBasicAuthTest.php b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutXmlBasicAuthTest.php
index 9645aedaea..24b1333364 100644
--- a/core/modules/shortcut/tests/src/Functional/Rest/ShortcutXmlBasicAuthTest.php
+++ b/core/modules/shortcut/tests/src/Functional/Rest/ShortcutXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ShortcutXmlBasicAuthTest extends ShortcutResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php b/core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php
index a2282b1ddf..e89ec20938 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php
@@ -18,7 +18,7 @@ class ShortcutCacheTagsTest extends EntityCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut'];
+  protected static $modules = ['shortcut'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php b/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
index 238ee4fa9b..fe2c76714d 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
@@ -24,7 +24,7 @@ class ShortcutLinksTest extends ShortcutTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test', 'views', 'block'];
+  protected static $modules = ['router_test', 'views', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutSetsTest.php b/core/modules/shortcut/tests/src/Functional/ShortcutSetsTest.php
index b897df752d..76da164dce 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutSetsTest.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutSetsTest.php
@@ -16,7 +16,7 @@ class ShortcutSetsTest extends ShortcutTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php b/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
index 3f9cc87be3..94d78fa052 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'toolbar', 'shortcut'];
+  protected static $modules = ['node', 'toolbar', 'shortcut'];
 
   /**
    * User with permission to administer shortcuts.
diff --git a/core/modules/shortcut/tests/src/Functional/ShortcutTranslationUITest.php b/core/modules/shortcut/tests/src/Functional/ShortcutTranslationUITest.php
index 5861d99838..77d3466366 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutTranslationUITest.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutTranslationUITest.php
@@ -23,7 +23,7 @@ class ShortcutTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'content_translation',
     'link',
diff --git a/core/modules/shortcut/tests/src/Kernel/Migrate/MigrateShortcutStubTest.php b/core/modules/shortcut/tests/src/Kernel/Migrate/MigrateShortcutStubTest.php
index f5b01d98af..e52b327cd1 100644
--- a/core/modules/shortcut/tests/src/Kernel/Migrate/MigrateShortcutStubTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Migrate/MigrateShortcutStubTest.php
@@ -17,7 +17,7 @@ class MigrateShortcutStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut', 'link'];
+  protected static $modules = ['shortcut', 'link'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetTest.php b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetTest.php
index b6543723db..d68c9d8c86 100644
--- a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetTest.php
@@ -18,7 +18,7 @@ class MigrateShortcutSetTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'link',
     'field',
     'shortcut',
diff --git a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetUsersTest.php b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetUsersTest.php
index ae939569cf..b14788143a 100644
--- a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetUsersTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutSetUsersTest.php
@@ -17,7 +17,7 @@ class MigrateShortcutSetUsersTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'link',
     'field',
     'shortcut',
diff --git a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutTest.php b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutTest.php
index e685151a5b..f81cc24660 100644
--- a/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Migrate/d7/MigrateShortcutTest.php
@@ -18,7 +18,7 @@ class MigrateShortcutTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'link',
     'field',
     'shortcut',
diff --git a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetTest.php b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetTest.php
index e1982de648..302f80dbe6 100644
--- a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetTest.php
@@ -16,7 +16,7 @@ class ShortcutSetTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut', 'migrate_drupal'];
+  protected static $modules = ['shortcut', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetUsersTest.php b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetUsersTest.php
index 035aec31c9..5dc83f79ef 100644
--- a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetUsersTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutSetUsersTest.php
@@ -16,7 +16,7 @@ class ShortcutSetUsersTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut', 'migrate_drupal'];
+  protected static $modules = ['shortcut', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutTest.php b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutTest.php
index 4435e81b2f..afd1e1d965 100644
--- a/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/Plugin/migrate/source/d7/ShortcutTest.php
@@ -16,7 +16,7 @@ class ShortcutTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut', 'migrate_drupal'];
+  protected static $modules = ['shortcut', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/shortcut/tests/src/Kernel/ShortcutSevenIntegrationTest.php b/core/modules/shortcut/tests/src/Kernel/ShortcutSevenIntegrationTest.php
index 0d58c31659..2e43bf700c 100644
--- a/core/modules/shortcut/tests/src/Kernel/ShortcutSevenIntegrationTest.php
+++ b/core/modules/shortcut/tests/src/Kernel/ShortcutSevenIntegrationTest.php
@@ -11,7 +11,7 @@
  */
 class ShortcutSevenIntegrationTest extends KernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests shortcut_install() and shortcut_uninstall().
diff --git a/core/modules/simpletest/src/KernelTestBase.php b/core/modules/simpletest/src/KernelTestBase.php
index acf6b3e899..e84bb101a9 100644
--- a/core/modules/simpletest/src/KernelTestBase.php
+++ b/core/modules/simpletest/src/KernelTestBase.php
@@ -87,7 +87,7 @@
    *
    * @var array
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   private $moduleFiles;
   private $themeFiles;
diff --git a/core/modules/simpletest/src/Tests/BrokenSetUpTest.php b/core/modules/simpletest/src/Tests/BrokenSetUpTest.php
index febb9cfda7..6fb4c312f6 100644
--- a/core/modules/simpletest/src/Tests/BrokenSetUpTest.php
+++ b/core/modules/simpletest/src/Tests/BrokenSetUpTest.php
@@ -22,7 +22,7 @@ class BrokenSetUpTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * The path to the shared trigger file.
diff --git a/core/modules/simpletest/src/Tests/BrowserTest.php b/core/modules/simpletest/src/Tests/BrowserTest.php
index fdfaff851d..bbed3de986 100644
--- a/core/modules/simpletest/src/Tests/BrowserTest.php
+++ b/core/modules/simpletest/src/Tests/BrowserTest.php
@@ -23,7 +23,7 @@ class BrowserTest extends WebTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/simpletest/src/Tests/InstallationProfileModuleTestsTest.php b/core/modules/simpletest/src/Tests/InstallationProfileModuleTestsTest.php
index 7a7a0367af..43b6b9ccc6 100644
--- a/core/modules/simpletest/src/Tests/InstallationProfileModuleTestsTest.php
+++ b/core/modules/simpletest/src/Tests/InstallationProfileModuleTestsTest.php
@@ -16,7 +16,7 @@ class InstallationProfileModuleTestsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * An administrative user with permission to adminsiter unit tests.
diff --git a/core/modules/simpletest/src/Tests/KernelTestBaseTest.php b/core/modules/simpletest/src/Tests/KernelTestBaseTest.php
index fc0d918b8a..29077d40e4 100644
--- a/core/modules/simpletest/src/Tests/KernelTestBaseTest.php
+++ b/core/modules/simpletest/src/Tests/KernelTestBaseTest.php
@@ -20,7 +20,7 @@ class KernelTestBaseTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/simpletest/src/Tests/MissingCheckedRequirementsTest.php b/core/modules/simpletest/src/Tests/MissingCheckedRequirementsTest.php
index d6fe19964a..ae0e664b28 100644
--- a/core/modules/simpletest/src/Tests/MissingCheckedRequirementsTest.php
+++ b/core/modules/simpletest/src/Tests/MissingCheckedRequirementsTest.php
@@ -16,7 +16,7 @@ class MissingCheckedRequirementsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/simpletest/src/Tests/SimpleTestBrowserTest.php b/core/modules/simpletest/src/Tests/SimpleTestBrowserTest.php
index 957391db76..ee3a19cf7b 100644
--- a/core/modules/simpletest/src/Tests/SimpleTestBrowserTest.php
+++ b/core/modules/simpletest/src/Tests/SimpleTestBrowserTest.php
@@ -18,7 +18,7 @@ class SimpleTestBrowserTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest', 'test_page_test'];
+  protected static $modules = ['simpletest', 'test_page_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/simpletest/src/Tests/SimpleTestErrorCollectorTest.php b/core/modules/simpletest/src/Tests/SimpleTestErrorCollectorTest.php
index b401fc9994..5bfc74f1ee 100644
--- a/core/modules/simpletest/src/Tests/SimpleTestErrorCollectorTest.php
+++ b/core/modules/simpletest/src/Tests/SimpleTestErrorCollectorTest.php
@@ -16,7 +16,7 @@ class SimpleTestErrorCollectorTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test', 'error_test'];
+  protected static $modules = ['system_test', 'error_test'];
 
   /**
    * Errors triggered during the test.
diff --git a/core/modules/simpletest/src/Tests/SimpleTestInstallBatchTest.php b/core/modules/simpletest/src/Tests/SimpleTestInstallBatchTest.php
index 5663ad9cdc..29da05d28a 100644
--- a/core/modules/simpletest/src/Tests/SimpleTestInstallBatchTest.php
+++ b/core/modules/simpletest/src/Tests/SimpleTestInstallBatchTest.php
@@ -20,7 +20,7 @@ class SimpleTestInstallBatchTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest', 'simpletest_test', 'entity_test'];
+  protected static $modules = ['simpletest', 'simpletest_test', 'entity_test'];
 
   /**
    * Tests loading entities created in a batch in simpletest_test_install().
diff --git a/core/modules/simpletest/src/Tests/SimpleTestTest.php b/core/modules/simpletest/src/Tests/SimpleTestTest.php
index 42759c255a..1364d3cdf3 100644
--- a/core/modules/simpletest/src/Tests/SimpleTestTest.php
+++ b/core/modules/simpletest/src/Tests/SimpleTestTest.php
@@ -20,7 +20,7 @@ class SimpleTestTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * The results array that has been parsed by getTestResults().
diff --git a/core/modules/simpletest/src/Tests/UiPhpUnitOutputTest.php b/core/modules/simpletest/src/Tests/UiPhpUnitOutputTest.php
index e032cef941..0b5f1707bc 100644
--- a/core/modules/simpletest/src/Tests/UiPhpUnitOutputTest.php
+++ b/core/modules/simpletest/src/Tests/UiPhpUnitOutputTest.php
@@ -19,7 +19,7 @@ class UiPhpUnitOutputTest extends WebTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * Tests that PHPUnit output in the Simpletest UI looks good.
diff --git a/core/modules/simpletest/tests/src/Functional/FolderTest.php b/core/modules/simpletest/tests/src/Functional/FolderTest.php
index e57813fa71..d2c93c54f0 100644
--- a/core/modules/simpletest/tests/src/Functional/FolderTest.php
+++ b/core/modules/simpletest/tests/src/Functional/FolderTest.php
@@ -17,7 +17,7 @@ class FolderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   public function testFolderSetup() {
     $directory = file_default_scheme() . '://styles';
diff --git a/core/modules/simpletest/tests/src/Functional/OtherInstallationProfileTestsTest.php b/core/modules/simpletest/tests/src/Functional/OtherInstallationProfileTestsTest.php
index 972495f575..3088dc8f24 100644
--- a/core/modules/simpletest/tests/src/Functional/OtherInstallationProfileTestsTest.php
+++ b/core/modules/simpletest/tests/src/Functional/OtherInstallationProfileTestsTest.php
@@ -17,7 +17,7 @@ class OtherInstallationProfileTestsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * Use the Minimal profile.
diff --git a/core/modules/simpletest/tests/src/Kernel/Cache/Context/TestDiscoveryCacheContextTest.php b/core/modules/simpletest/tests/src/Kernel/Cache/Context/TestDiscoveryCacheContextTest.php
index 25b2af92e4..01aac836db 100644
--- a/core/modules/simpletest/tests/src/Kernel/Cache/Context/TestDiscoveryCacheContextTest.php
+++ b/core/modules/simpletest/tests/src/Kernel/Cache/Context/TestDiscoveryCacheContextTest.php
@@ -14,7 +14,7 @@ class TestDiscoveryCacheContextTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * Tests that test context hashes are unique.
diff --git a/core/modules/simpletest/tests/src/Kernel/Migrate/d6/MigrateSimpletestConfigsTest.php b/core/modules/simpletest/tests/src/Kernel/Migrate/d6/MigrateSimpletestConfigsTest.php
index f8f9ffb02c..fe70c16b4e 100644
--- a/core/modules/simpletest/tests/src/Kernel/Migrate/d6/MigrateSimpletestConfigsTest.php
+++ b/core/modules/simpletest/tests/src/Kernel/Migrate/d6/MigrateSimpletestConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateSimpletestConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/simpletest/tests/src/Kernel/Migrate/d7/MigrateSimpletestSettingsTest.php b/core/modules/simpletest/tests/src/Kernel/Migrate/d7/MigrateSimpletestSettingsTest.php
index 6eba6339c8..cc8bd1d2ef 100644
--- a/core/modules/simpletest/tests/src/Kernel/Migrate/d7/MigrateSimpletestSettingsTest.php
+++ b/core/modules/simpletest/tests/src/Kernel/Migrate/d7/MigrateSimpletestSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateSimpletestSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/simpletest/tests/src/Kernel/SimpletestDeprecationTest.php b/core/modules/simpletest/tests/src/Kernel/SimpletestDeprecationTest.php
index 384f8c1b9b..2a5f0a4a77 100644
--- a/core/modules/simpletest/tests/src/Kernel/SimpletestDeprecationTest.php
+++ b/core/modules/simpletest/tests/src/Kernel/SimpletestDeprecationTest.php
@@ -12,7 +12,7 @@
  */
 class SimpletestDeprecationTest extends KernelTestBase {
 
-  public static $modules = ['simpletest'];
+  protected static $modules = ['simpletest'];
 
   /**
    * @expectedDeprecation The simpletest_phpunit_configuration_filepath function is deprecated since version 8.4.x and will be removed in 9.0.0.
diff --git a/core/modules/simpletest/tests/src/Kernel/TestDiscoveryDeprecationTest.php b/core/modules/simpletest/tests/src/Kernel/TestDiscoveryDeprecationTest.php
index 6d4f44888a..c8edb7732f 100644
--- a/core/modules/simpletest/tests/src/Kernel/TestDiscoveryDeprecationTest.php
+++ b/core/modules/simpletest/tests/src/Kernel/TestDiscoveryDeprecationTest.php
@@ -15,7 +15,7 @@ class TestDiscoveryDeprecationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['simpletest', 'simpletest_deprecation_test'];
+  protected static $modules = ['simpletest', 'simpletest_deprecation_test'];
 
   /**
    * @expectedDeprecation The deprecated alter hook hook_simpletest_alter() is implemented in these functions: simpletest_deprecation_test_simpletest_alter. Convert your test to a PHPUnit-based one and implement test listeners. See: https://www.drupal.org/node/2939892
diff --git a/core/modules/statistics/src/Tests/StatisticsTestBase.php b/core/modules/statistics/src/Tests/StatisticsTestBase.php
index 4f530cf9cd..6da2f2cc01 100644
--- a/core/modules/statistics/src/Tests/StatisticsTestBase.php
+++ b/core/modules/statistics/src/Tests/StatisticsTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'ban', 'statistics'];
+  protected static $modules = ['node', 'block', 'ban', 'statistics'];
 
   /**
    * User with permissions to ban IP's.
diff --git a/core/modules/statistics/src/Tests/Views/IntegrationTest.php b/core/modules/statistics/src/Tests/Views/IntegrationTest.php
index 740ecf5e53..0d4088f0ae 100644
--- a/core/modules/statistics/src/Tests/Views/IntegrationTest.php
+++ b/core/modules/statistics/src/Tests/Views/IntegrationTest.php
@@ -19,7 +19,7 @@ class IntegrationTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['statistics', 'statistics_test_views', 'node'];
+  protected static $modules = ['statistics', 'statistics_test_views', 'node'];
 
   /**
    * Stores the user object that accesses the page.
diff --git a/core/modules/statistics/tests/src/Functional/StatisticsAdminTest.php b/core/modules/statistics/tests/src/Functional/StatisticsAdminTest.php
index 1c714dc689..f43f2789a0 100644
--- a/core/modules/statistics/tests/src/Functional/StatisticsAdminTest.php
+++ b/core/modules/statistics/tests/src/Functional/StatisticsAdminTest.php
@@ -19,7 +19,7 @@ class StatisticsAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'statistics'];
+  protected static $modules = ['node', 'statistics'];
 
   /**
    * A user that has permission to administer statistics.
diff --git a/core/modules/statistics/tests/src/Functional/StatisticsAttachedTest.php b/core/modules/statistics/tests/src/Functional/StatisticsAttachedTest.php
index 90a62093b6..ef734963db 100644
--- a/core/modules/statistics/tests/src/Functional/StatisticsAttachedTest.php
+++ b/core/modules/statistics/tests/src/Functional/StatisticsAttachedTest.php
@@ -17,7 +17,7 @@ class StatisticsAttachedTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'statistics'];
+  protected static $modules = ['node', 'statistics'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/statistics/tests/src/Functional/StatisticsLoggingTest.php b/core/modules/statistics/tests/src/Functional/StatisticsLoggingTest.php
index ea87a7cd44..e73fd89195 100644
--- a/core/modules/statistics/tests/src/Functional/StatisticsLoggingTest.php
+++ b/core/modules/statistics/tests/src/Functional/StatisticsLoggingTest.php
@@ -20,7 +20,7 @@ class StatisticsLoggingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'statistics', 'block', 'locale'];
+  protected static $modules = ['node', 'statistics', 'block', 'locale'];
 
   /**
    * User with permissions to create and edit pages.
diff --git a/core/modules/statistics/tests/src/Functional/StatisticsTestBase.php b/core/modules/statistics/tests/src/Functional/StatisticsTestBase.php
index 3be95e2ab6..d55db18459 100644
--- a/core/modules/statistics/tests/src/Functional/StatisticsTestBase.php
+++ b/core/modules/statistics/tests/src/Functional/StatisticsTestBase.php
@@ -14,7 +14,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'ban', 'statistics'];
+  protected static $modules = ['node', 'block', 'ban', 'statistics'];
 
   /**
    * User with permissions to ban IP's.
diff --git a/core/modules/statistics/tests/src/FunctionalJavascript/StatisticsLoggingTest.php b/core/modules/statistics/tests/src/FunctionalJavascript/StatisticsLoggingTest.php
index acd103e9f6..95d87bfd2a 100644
--- a/core/modules/statistics/tests/src/FunctionalJavascript/StatisticsLoggingTest.php
+++ b/core/modules/statistics/tests/src/FunctionalJavascript/StatisticsLoggingTest.php
@@ -17,7 +17,7 @@ class StatisticsLoggingTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'statistics', 'language'];
+  protected static $modules = ['node', 'statistics', 'language'];
 
   /**
    * Node for tests.
diff --git a/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateNodeCounterTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateNodeCounterTest.php
index 29a35fb339..f87c7b7439 100644
--- a/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateNodeCounterTest.php
+++ b/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateNodeCounterTest.php
@@ -14,7 +14,7 @@ class MigrateNodeCounterTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php
index a9c18a733b..18cb50a112 100644
--- a/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php
+++ b/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateStatisticsConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['statistics'];
+  protected static $modules = ['statistics'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateNodeCounterTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateNodeCounterTest.php
index 1401e60fd4..7a0d3266fa 100644
--- a/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateNodeCounterTest.php
+++ b/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateNodeCounterTest.php
@@ -14,7 +14,7 @@ class MigrateNodeCounterTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_translation',
     'language',
     'menu_ui',
diff --git a/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateStatisticsConfigsTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateStatisticsConfigsTest.php
index 36e270d8f6..e069b3cfd7 100644
--- a/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateStatisticsConfigsTest.php
+++ b/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateStatisticsConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateStatisticsConfigsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['statistics'];
+  protected static $modules = ['statistics'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/statistics/tests/src/Kernel/Plugin/migrate/source/NodeCounterTest.php b/core/modules/statistics/tests/src/Kernel/Plugin/migrate/source/NodeCounterTest.php
index 0cbc76afec..f2a64c4416 100644
--- a/core/modules/statistics/tests/src/Kernel/Plugin/migrate/source/NodeCounterTest.php
+++ b/core/modules/statistics/tests/src/Kernel/Plugin/migrate/source/NodeCounterTest.php
@@ -16,7 +16,7 @@ class NodeCounterTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal', 'statistics'];
+  protected static $modules = ['migrate_drupal', 'statistics'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/syslog/tests/src/Functional/SyslogTest.php b/core/modules/syslog/tests/src/Functional/SyslogTest.php
index 11b577f2f2..ba0cf61eb4 100644
--- a/core/modules/syslog/tests/src/Functional/SyslogTest.php
+++ b/core/modules/syslog/tests/src/Functional/SyslogTest.php
@@ -16,7 +16,7 @@ class SyslogTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['syslog'];
+  protected static $modules = ['syslog'];
 
   /**
    * Tests the syslog settings page.
diff --git a/core/modules/syslog/tests/src/Kernel/Migrate/d6/MigrateSyslogConfigsTest.php b/core/modules/syslog/tests/src/Kernel/Migrate/d6/MigrateSyslogConfigsTest.php
index 935af8d8aa..05526264f3 100644
--- a/core/modules/syslog/tests/src/Kernel/Migrate/d6/MigrateSyslogConfigsTest.php
+++ b/core/modules/syslog/tests/src/Kernel/Migrate/d6/MigrateSyslogConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateSyslogConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['syslog'];
+  protected static $modules = ['syslog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/syslog/tests/src/Kernel/Migrate/d7/MigrateSyslogConfigsTest.php b/core/modules/syslog/tests/src/Kernel/Migrate/d7/MigrateSyslogConfigsTest.php
index ef5d8c305d..4e50cdcd79 100644
--- a/core/modules/syslog/tests/src/Kernel/Migrate/d7/MigrateSyslogConfigsTest.php
+++ b/core/modules/syslog/tests/src/Kernel/Migrate/d7/MigrateSyslogConfigsTest.php
@@ -19,7 +19,7 @@ class MigrateSyslogConfigsTest extends MigrateDrupal7TestBase {
    *
    * @var array
    */
-  public static $modules = ['syslog'];
+  protected static $modules = ['syslog'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/syslog/tests/src/Kernel/SyslogTest.php b/core/modules/syslog/tests/src/Kernel/SyslogTest.php
index 3b2a587a40..88a059de21 100644
--- a/core/modules/syslog/tests/src/Kernel/SyslogTest.php
+++ b/core/modules/syslog/tests/src/Kernel/SyslogTest.php
@@ -13,7 +13,7 @@
  */
 class SyslogTest extends KernelTestBase {
 
-  public static $modules = ['syslog', 'syslog_test'];
+  protected static $modules = ['syslog', 'syslog_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Tests/Ajax/AjaxTestBase.php b/core/modules/system/src/Tests/Ajax/AjaxTestBase.php
index 66e06c88a4..067569242e 100644
--- a/core/modules/system/src/Tests/Ajax/AjaxTestBase.php
+++ b/core/modules/system/src/Tests/Ajax/AjaxTestBase.php
@@ -14,7 +14,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'ajax_test', 'ajax_forms_test'];
+  protected static $modules = ['node', 'ajax_test', 'ajax_forms_test'];
 
   /**
    * Asserts the array of Ajax commands contains the searched command.
diff --git a/core/modules/system/src/Tests/Ajax/DialogTest.php b/core/modules/system/src/Tests/Ajax/DialogTest.php
index 76ab6fb160..2e35e57606 100644
--- a/core/modules/system/src/Tests/Ajax/DialogTest.php
+++ b/core/modules/system/src/Tests/Ajax/DialogTest.php
@@ -19,7 +19,7 @@ class DialogTest extends AjaxTestBase {
    *
    * @var array
    */
-  public static $modules = ['ajax_test', 'ajax_forms_test', 'contact'];
+  protected static $modules = ['ajax_test', 'ajax_forms_test', 'contact'];
 
   /**
    * Test sending non-JS and AJAX requests to open and manipulate modals.
diff --git a/core/modules/system/src/Tests/Ajax/MultiFormTest.php b/core/modules/system/src/Tests/Ajax/MultiFormTest.php
index 96844ed051..be15c9e974 100644
--- a/core/modules/system/src/Tests/Ajax/MultiFormTest.php
+++ b/core/modules/system/src/Tests/Ajax/MultiFormTest.php
@@ -19,7 +19,7 @@ class MultiFormTest extends AjaxTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Condition/ConditionFormTest.php b/core/modules/system/src/Tests/Condition/ConditionFormTest.php
index 42945b250a..c853798c1e 100644
--- a/core/modules/system/src/Tests/Condition/ConditionFormTest.php
+++ b/core/modules/system/src/Tests/Condition/ConditionFormTest.php
@@ -16,7 +16,7 @@
  */
 class ConditionFormTest extends WebTestBase {
 
-  public static $modules = ['node', 'condition_test'];
+  protected static $modules = ['node', 'condition_test'];
 
   /**
    * Submit the condition_node_type_test_form to test condition forms.
diff --git a/core/modules/system/src/Tests/Database/DatabaseWebTestBase.php b/core/modules/system/src/Tests/Database/DatabaseWebTestBase.php
index 8a250baf35..84f022665e 100644
--- a/core/modules/system/src/Tests/Database/DatabaseWebTestBase.php
+++ b/core/modules/system/src/Tests/Database/DatabaseWebTestBase.php
@@ -20,7 +20,7 @@
    *
    * @var array
    */
-  public static $modules = ['database_test'];
+  protected static $modules = ['database_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
index 517e1c670e..49388dd5bc 100644
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -31,7 +31,7 @@
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field_test'];
+  protected static $modules = ['entity_test', 'field_test'];
 
   /**
    * The main entity used for testing.
diff --git a/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php b/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
index 9997ca5650..9546d40c94 100644
--- a/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = ['user', 'system', 'field', 'text', 'filter', 'entity_test'];
+  protected static $modules = ['user', 'system', 'field', 'text', 'filter', 'entity_test'];
 
   /**
    * The entity manager service.
diff --git a/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php b/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
index 030526eef9..729a5202a1 100644
--- a/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
+++ b/core/modules/system/src/Tests/Form/ElementsTableSelectTest.php
@@ -18,7 +18,7 @@ class ElementsTableSelectTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Test the display of checkboxes when #multiple is TRUE.
diff --git a/core/modules/system/src/Tests/Form/RebuildTest.php b/core/modules/system/src/Tests/Form/RebuildTest.php
index 2e138bdfb3..bd48f04d4c 100644
--- a/core/modules/system/src/Tests/Form/RebuildTest.php
+++ b/core/modules/system/src/Tests/Form/RebuildTest.php
@@ -21,7 +21,7 @@ class RebuildTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'form_test'];
+  protected static $modules = ['node', 'form_test'];
 
   /**
    * A user for testing.
diff --git a/core/modules/system/src/Tests/Form/StorageTest.php b/core/modules/system/src/Tests/Form/StorageTest.php
index a1f7fee3df..8f32596216 100644
--- a/core/modules/system/src/Tests/Form/StorageTest.php
+++ b/core/modules/system/src/Tests/Form/StorageTest.php
@@ -23,7 +23,7 @@ class StorageTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test', 'dblog'];
+  protected static $modules = ['form_test', 'dblog'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Form/TriggeringElementTest.php b/core/modules/system/src/Tests/Form/TriggeringElementTest.php
index fb59cb5e8a..54a403987a 100644
--- a/core/modules/system/src/Tests/Form/TriggeringElementTest.php
+++ b/core/modules/system/src/Tests/Form/TriggeringElementTest.php
@@ -16,7 +16,7 @@ class TriggeringElementTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Test the determination of the triggering element when no button
diff --git a/core/modules/system/src/Tests/Image/ToolkitTestBase.php b/core/modules/system/src/Tests/Image/ToolkitTestBase.php
index ef85f0c50b..7a3d09cd05 100644
--- a/core/modules/system/src/Tests/Image/ToolkitTestBase.php
+++ b/core/modules/system/src/Tests/Image/ToolkitTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = ['image_test'];
+  protected static $modules = ['image_test'];
 
   /**
    * The URI for the file.
diff --git a/core/modules/system/src/Tests/Module/ModuleTestBase.php b/core/modules/system/src/Tests/Module/ModuleTestBase.php
index 257bb879cf..02ee0bd87d 100644
--- a/core/modules/system/src/Tests/Module/ModuleTestBase.php
+++ b/core/modules/system/src/Tests/Module/ModuleTestBase.php
@@ -21,7 +21,7 @@
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/src/Tests/Pager/PagerTest.php b/core/modules/system/src/Tests/Pager/PagerTest.php
index 71413f283e..511e40e2ad 100644
--- a/core/modules/system/src/Tests/Pager/PagerTest.php
+++ b/core/modules/system/src/Tests/Pager/PagerTest.php
@@ -16,7 +16,7 @@ class PagerTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['dblog', 'pager_test'];
+  protected static $modules = ['dblog', 'pager_test'];
 
   /**
    * A user with permission to access site reports.
diff --git a/core/modules/system/src/Tests/Render/HtmlResponseAttachmentsTest.php b/core/modules/system/src/Tests/Render/HtmlResponseAttachmentsTest.php
index 6060fcc30c..3ef9cf1dc9 100644
--- a/core/modules/system/src/Tests/Render/HtmlResponseAttachmentsTest.php
+++ b/core/modules/system/src/Tests/Render/HtmlResponseAttachmentsTest.php
@@ -16,7 +16,7 @@ class HtmlResponseAttachmentsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['render_attached_test'];
+  protected static $modules = ['render_attached_test'];
 
   /**
    * Test rendering of ['#attached'].
diff --git a/core/modules/system/src/Tests/Render/UrlBubbleableMetadataBubblingTest.php b/core/modules/system/src/Tests/Render/UrlBubbleableMetadataBubblingTest.php
index a55037f74b..da60ac5d8e 100644
--- a/core/modules/system/src/Tests/Render/UrlBubbleableMetadataBubblingTest.php
+++ b/core/modules/system/src/Tests/Render/UrlBubbleableMetadataBubblingTest.php
@@ -17,7 +17,7 @@ class UrlBubbleableMetadataBubblingTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['cache_test'];
+  protected static $modules = ['cache_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Tests/Routing/DestinationTest.php b/core/modules/system/src/Tests/Routing/DestinationTest.php
index d959c7ad4a..c6669af0ec 100644
--- a/core/modules/system/src/Tests/Routing/DestinationTest.php
+++ b/core/modules/system/src/Tests/Routing/DestinationTest.php
@@ -20,7 +20,7 @@ class DestinationTest extends WebTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   /**
    * Tests that $_GET/$_REQUEST['destination'] only contain internal URLs.
diff --git a/core/modules/system/src/Tests/Routing/RouterTest.php b/core/modules/system/src/Tests/Routing/RouterTest.php
index 83a9c55b39..41306da9cd 100644
--- a/core/modules/system/src/Tests/Routing/RouterTest.php
+++ b/core/modules/system/src/Tests/Routing/RouterTest.php
@@ -21,7 +21,7 @@ class RouterTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test'];
+  protected static $modules = ['router_test'];
 
   /**
    * Confirms that our FinishResponseSubscriber logic works properly.
diff --git a/core/modules/system/src/Tests/Session/SessionAuthenticationTest.php b/core/modules/system/src/Tests/Session/SessionAuthenticationTest.php
index ffdc08d192..48f629e274 100644
--- a/core/modules/system/src/Tests/Session/SessionAuthenticationTest.php
+++ b/core/modules/system/src/Tests/Session/SessionAuthenticationTest.php
@@ -25,7 +25,7 @@ class SessionAuthenticationTest extends WebTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth', 'session_test'];
+  protected static $modules = ['basic_auth', 'session_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Tests/Session/SessionHttpsTest.php b/core/modules/system/src/Tests/Session/SessionHttpsTest.php
index 6ba70da52b..81e3b66aaf 100644
--- a/core/modules/system/src/Tests/Session/SessionHttpsTest.php
+++ b/core/modules/system/src/Tests/Session/SessionHttpsTest.php
@@ -33,7 +33,7 @@ class SessionHttpsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['session_test'];
+  protected static $modules = ['session_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Session/SessionTest.php b/core/modules/system/src/Tests/Session/SessionTest.php
index 0f219c5036..f7efea7c93 100644
--- a/core/modules/system/src/Tests/Session/SessionTest.php
+++ b/core/modules/system/src/Tests/Session/SessionTest.php
@@ -16,7 +16,7 @@ class SessionTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['session_test'];
+  protected static $modules = ['session_test'];
 
   protected $dumpHeaders = TRUE;
 
diff --git a/core/modules/system/src/Tests/Session/StackSessionHandlerIntegrationTest.php b/core/modules/system/src/Tests/Session/StackSessionHandlerIntegrationTest.php
index ac368685db..da5736354d 100644
--- a/core/modules/system/src/Tests/Session/StackSessionHandlerIntegrationTest.php
+++ b/core/modules/system/src/Tests/Session/StackSessionHandlerIntegrationTest.php
@@ -16,7 +16,7 @@ class StackSessionHandlerIntegrationTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['session_test'];
+  protected static $modules = ['session_test'];
 
   /**
    * Tests a request.
diff --git a/core/modules/system/src/Tests/System/ErrorHandlerTest.php b/core/modules/system/src/Tests/System/ErrorHandlerTest.php
index dc661fec91..04cb17526c 100644
--- a/core/modules/system/src/Tests/System/ErrorHandlerTest.php
+++ b/core/modules/system/src/Tests/System/ErrorHandlerTest.php
@@ -17,7 +17,7 @@ class ErrorHandlerTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['error_test'];
+  protected static $modules = ['error_test'];
 
   /**
    * Test the error handler.
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonAnonTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonAnonTest.php
index 77988aa037..9b577c104b 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonAnonTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonAnonTest.php
@@ -17,7 +17,7 @@ class EntityTestBundleHalJsonAnonTest extends EntityTestBundleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonBasicAuthTest.php
index 47e44d2d18..d49858b4a7 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EntityTestBundleHalJsonBasicAuthTest extends EntityTestBundleResourceTestB
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonCookieTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonCookieTest.php
index 3e8b442de7..c5ba2877fb 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonCookieTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestBundleHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityTestBundleHalJsonCookieTest extends EntityTestBundleResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonAnonTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonAnonTest.php
index c272a1aa6f..6c77db81ac 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonAnonTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonAnonTest.php
@@ -20,7 +20,7 @@ class EntityTestHalJsonAnonTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonBasicAuthTest.php
index 18fad4beed..c0d5885263 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestHalJsonBasicAuthTest extends EntityTestHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonInternalPropertyNormalizerTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonInternalPropertyNormalizerTest.php
index 73d70d3ff6..0739a34517 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonInternalPropertyNormalizerTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestHalJsonInternalPropertyNormalizerTest.php
@@ -20,7 +20,7 @@ class EntityTestHalJsonInternalPropertyNormalizerTest extends EntityTestHalJsonA
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonAnonTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonAnonTest.php
index ca6e395351..7e39c8be33 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonAnonTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class EntityTestLabelHalJsonAnonTest extends EntityTestLabelResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonBasicAuthTest.php
index dfae2e4024..acbcc198f8 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestLabelHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestLabelHalJsonBasicAuthTest extends EntityTestLabelHalJsonAnonTest
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestMapFieldHalJsonAnonTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestMapFieldHalJsonAnonTest.php
index af1ef4ceaa..f4b0df9da1 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestMapFieldHalJsonAnonTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Hal/EntityTestMapFieldHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class EntityTestMapFieldHalJsonAnonTest extends EntityTestMapFieldResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleJsonBasicAuthTest.php
index d1a7adbc9e..8a193b9662 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestBundleJsonBasicAuthTest extends EntityTestBundleResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleResourceTestBase.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleResourceTestBase.php
index cf167bc6eb..e0b9e0ddaa 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleResourceTestBase.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleXmlBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleXmlBasicAuthTest.php
index 701c15ba9f..e39211996b 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleXmlBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestBundleXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityTestBundleXmlBasicAuthTest extends EntityTestBundleResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestJsonBasicAuthTest.php
index cd647e8fe3..dd2f06f45a 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestJsonBasicAuthTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelJsonBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelJsonBasicAuthTest.php
index 61cfea15b2..eb43d0293f 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelJsonBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityTestLabelJsonBasicAuthTest extends EntityTestLabelResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelResourceTestBase.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelResourceTestBase.php
index 08a6552f65..121b8ed3bf 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelResourceTestBase.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelXmlBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelXmlBasicAuthTest.php
index e671098f2f..6c9030e3dd 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelXmlBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestLabelXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityTestLabelXmlBasicAuthTest extends EntityTestLabelResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
index eae226cfa0..4a6413af82 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestMapFieldResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestResourceTestBase.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestResourceTestBase.php
index 2210f97d6f..1b6428a832 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestResourceTestBase.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestTextItemNormalizerTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestTextItemNormalizerTest.php
index 3ae0044aee..f094f6f11b 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestTextItemNormalizerTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestTextItemNormalizerTest.php
@@ -17,7 +17,7 @@ class EntityTestTextItemNormalizerTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter_test'];
+  protected static $modules = ['filter_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestXmlBasicAuthTest.php b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestXmlBasicAuthTest.php
index d0501afb97..66622c587a 100644
--- a/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestXmlBasicAuthTest.php
+++ b/core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityTestXmlBasicAuthTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php b/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
index c786722123..3eafbdcf45 100644
--- a/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
+++ b/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
@@ -19,7 +19,7 @@ class OffCanvasDialogTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['ajax_test'];
+  protected static $modules = ['ajax_test'];
 
   /**
    * Test sending AJAX requests to open and manipulate off-canvas dialog.
diff --git a/core/modules/system/tests/src/Functional/Batch/PageTest.php b/core/modules/system/tests/src/Functional/Batch/PageTest.php
index b1e46a2ea5..957c802261 100644
--- a/core/modules/system/tests/src/Functional/Batch/PageTest.php
+++ b/core/modules/system/tests/src/Functional/Batch/PageTest.php
@@ -16,7 +16,7 @@ class PageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['batch_test'];
+  protected static $modules = ['batch_test'];
 
   /**
    * Tests that the batch API progress page uses the correct theme.
diff --git a/core/modules/system/tests/src/Functional/Batch/ProcessingTest.php b/core/modules/system/tests/src/Functional/Batch/ProcessingTest.php
index 97dc6e7a5f..92680a09a4 100644
--- a/core/modules/system/tests/src/Functional/Batch/ProcessingTest.php
+++ b/core/modules/system/tests/src/Functional/Batch/ProcessingTest.php
@@ -17,7 +17,7 @@ class ProcessingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['batch_test', 'test_page_test'];
+  protected static $modules = ['batch_test', 'test_page_test'];
 
   /**
    * Tests batches triggered outside of form submission.
diff --git a/core/modules/system/tests/src/Functional/Bootstrap/DrupalMessengerServiceTest.php b/core/modules/system/tests/src/Functional/Bootstrap/DrupalMessengerServiceTest.php
index 51404ef18d..f70f4dda2e 100644
--- a/core/modules/system/tests/src/Functional/Bootstrap/DrupalMessengerServiceTest.php
+++ b/core/modules/system/tests/src/Functional/Bootstrap/DrupalMessengerServiceTest.php
@@ -17,7 +17,7 @@ class DrupalMessengerServiceTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   /**
    * Tests Messenger service.
diff --git a/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php b/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php
index 78fb983a61..d2ff3d3b74 100644
--- a/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php
+++ b/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php
@@ -17,7 +17,7 @@ class SessionExistsCacheContextTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['session_exists_cache_context_test'];
+  protected static $modules = ['session_exists_cache_context_test'];
 
   /**
    * Tests \Drupal\Core\Cache\Context\SessionExistsCacheContext::getContext().
diff --git a/core/modules/system/tests/src/Functional/Common/AlterTest.php b/core/modules/system/tests/src/Functional/Common/AlterTest.php
index e529e9d1c2..981157bf25 100644
--- a/core/modules/system/tests/src/Functional/Common/AlterTest.php
+++ b/core/modules/system/tests/src/Functional/Common/AlterTest.php
@@ -16,7 +16,7 @@ class AlterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'common_test'];
+  protected static $modules = ['block', 'common_test'];
 
   /**
    * Tests if the theme has been altered.
diff --git a/core/modules/system/tests/src/Functional/Common/EarlyRenderingControllerTest.php b/core/modules/system/tests/src/Functional/Common/EarlyRenderingControllerTest.php
index 9d6c0af5d1..633f09f4e3 100644
--- a/core/modules/system/tests/src/Functional/Common/EarlyRenderingControllerTest.php
+++ b/core/modules/system/tests/src/Functional/Common/EarlyRenderingControllerTest.php
@@ -20,7 +20,7 @@ class EarlyRenderingControllerTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'early_rendering_controller_test'];
+  protected static $modules = ['system', 'early_rendering_controller_test'];
 
   /**
    * Tests theme preprocess functions being able to attach assets.
diff --git a/core/modules/system/tests/src/Functional/Common/RenderWebTest.php b/core/modules/system/tests/src/Functional/Common/RenderWebTest.php
index 7856f94fb1..62ab7be166 100644
--- a/core/modules/system/tests/src/Functional/Common/RenderWebTest.php
+++ b/core/modules/system/tests/src/Functional/Common/RenderWebTest.php
@@ -21,7 +21,7 @@ class RenderWebTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['common_test'];
+  protected static $modules = ['common_test'];
 
   /**
    * Asserts the cache context for the wrapper format is always present.
diff --git a/core/modules/system/tests/src/Functional/Common/UrlTest.php b/core/modules/system/tests/src/Functional/Common/UrlTest.php
index 8e4d7b121c..b4ceaedb5f 100644
--- a/core/modules/system/tests/src/Functional/Common/UrlTest.php
+++ b/core/modules/system/tests/src/Functional/Common/UrlTest.php
@@ -20,7 +20,7 @@
  */
 class UrlTest extends BrowserTestBase {
 
-  public static $modules = ['common_test', 'url_alter_test'];
+  protected static $modules = ['common_test', 'url_alter_test'];
 
   /**
    * Confirms that invalid URLs are filtered in link generating functions.
diff --git a/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php b/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
index 0bb9016c48..608c32b1ff 100644
--- a/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
+++ b/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
@@ -17,7 +17,7 @@ class CsrfRequestHeaderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'csrf_test'];
+  protected static $modules = ['system', 'csrf_test'];
 
   /**
    * Tests access to routes protected by CSRF request header requirements.
diff --git a/core/modules/system/tests/src/Functional/Database/DatabaseTestBase.php b/core/modules/system/tests/src/Functional/Database/DatabaseTestBase.php
index a28c1dba23..9193ee1032 100644
--- a/core/modules/system/tests/src/Functional/Database/DatabaseTestBase.php
+++ b/core/modules/system/tests/src/Functional/Database/DatabaseTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['database_test'];
+  protected static $modules = ['database_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php b/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
index e7d08502f3..814787e174 100644
--- a/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
+++ b/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
@@ -14,7 +14,7 @@ class TemporaryQueryTest extends DatabaseTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['database_test'];
+  protected static $modules = ['database_test'];
 
   /**
    * Returns the number of rows of a table.
diff --git a/core/modules/system/tests/src/Functional/Datetime/DrupalDateTimeTest.php b/core/modules/system/tests/src/Functional/Datetime/DrupalDateTimeTest.php
index 488fa6ef42..bdf24b0d32 100644
--- a/core/modules/system/tests/src/Functional/Datetime/DrupalDateTimeTest.php
+++ b/core/modules/system/tests/src/Functional/Datetime/DrupalDateTimeTest.php
@@ -16,7 +16,7 @@ class DrupalDateTimeTest extends BrowserTestBase {
   /**
    * Set up required modules.
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * Test setup.
diff --git a/core/modules/system/tests/src/Functional/DrupalKernel/ContainerRebuildWebTest.php b/core/modules/system/tests/src/Functional/DrupalKernel/ContainerRebuildWebTest.php
index 828b92f289..37e64244ad 100644
--- a/core/modules/system/tests/src/Functional/DrupalKernel/ContainerRebuildWebTest.php
+++ b/core/modules/system/tests/src/Functional/DrupalKernel/ContainerRebuildWebTest.php
@@ -14,7 +14,7 @@ class ContainerRebuildWebTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['service_provider_test'];
+  protected static $modules = ['service_provider_test'];
 
   /**
    * Sets a different deployment identifier.
diff --git a/core/modules/system/tests/src/Functional/Entity/ConfigEntityImportTest.php b/core/modules/system/tests/src/Functional/Entity/ConfigEntityImportTest.php
index 88d9bb5d62..e32e8746c3 100644
--- a/core/modules/system/tests/src/Functional/Entity/ConfigEntityImportTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/ConfigEntityImportTest.php
@@ -21,7 +21,7 @@ class ConfigEntityImportTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['action', 'block', 'filter', 'image', 'search', 'search_extra_type', 'config_test'];
+  protected static $modules = ['action', 'block', 'filter', 'image', 'search', 'search_extra_type', 'config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php b/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php
index a16614f146..756ebb524b 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php
@@ -17,7 +17,7 @@ class EntityAddUITest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Tests the add page for an entity type using bundle entities.
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityCacheTagsTestBase.php b/core/modules/system/tests/src/Functional/Entity/EntityCacheTagsTestBase.php
index 447afbfa76..460a1bb451 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityCacheTagsTestBase.php
@@ -24,7 +24,7 @@
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field_test'];
+  protected static $modules = ['entity_test', 'field_test'];
 
   /**
    * The main entity used for testing.
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityFormTest.php b/core/modules/system/tests/src/Functional/Entity/EntityFormTest.php
index 4f0b7f0f71..9b85ea41b6 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityFormTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityFormTest.php
@@ -17,7 +17,7 @@ class EntityFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'language'];
+  protected static $modules = ['entity_test', 'language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityListBuilderTest.php b/core/modules/system/tests/src/Functional/Entity/EntityListBuilderTest.php
index 94225f4e97..fe6bb2a460 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityListBuilderTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityListBuilderTest.php
@@ -16,7 +16,7 @@ class EntityListBuilderTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityOperationsTest.php b/core/modules/system/tests/src/Functional/Entity/EntityOperationsTest.php
index b020f42870..fc17850675 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityOperationsTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityOperationsTest.php
@@ -16,7 +16,7 @@ class EntityOperationsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php b/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
index c037d12e3f..27f43ee33f 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
@@ -32,7 +32,7 @@ class EntityReferenceSelectionAccessTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'field', 'node', 'system', 'taxonomy', 'text', 'user'];
+  protected static $modules = ['comment', 'field', 'node', 'system', 'taxonomy', 'text', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
index bf8bcb337f..c5cbff2156 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
@@ -21,7 +21,7 @@ class EntityRevisionsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'language'];
+  protected static $modules = ['entity_test', 'language'];
 
   /**
    * A user with permission to administer entity_test content.
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityTranslationFormTest.php b/core/modules/system/tests/src/Functional/Entity/EntityTranslationFormTest.php
index e008e71e1f..4e735812d3 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityTranslationFormTest.php
@@ -19,7 +19,7 @@ class EntityTranslationFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'language', 'node'];
+  protected static $modules = ['entity_test', 'language', 'node'];
 
   protected $langcodes;
 
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityViewControllerTest.php b/core/modules/system/tests/src/Functional/Entity/EntityViewControllerTest.php
index 3637369753..2fc1c090cf 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityViewControllerTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityViewControllerTest.php
@@ -17,7 +17,7 @@ class EntityViewControllerTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Array of test entities.
diff --git a/core/modules/system/tests/src/Functional/Form/AlterTest.php b/core/modules/system/tests/src/Functional/Form/AlterTest.php
index 622a3d1ead..f857f47f22 100644
--- a/core/modules/system/tests/src/Functional/Form/AlterTest.php
+++ b/core/modules/system/tests/src/Functional/Form/AlterTest.php
@@ -17,7 +17,7 @@ class AlterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'form_test'];
+  protected static $modules = ['block', 'form_test'];
 
   /**
    * Tests execution order of hook_form_alter() and hook_form_FORM_ID_alter().
diff --git a/core/modules/system/tests/src/Functional/Form/ArbitraryRebuildTest.php b/core/modules/system/tests/src/Functional/Form/ArbitraryRebuildTest.php
index e35ac6d08a..9d243ba311 100644
--- a/core/modules/system/tests/src/Functional/Form/ArbitraryRebuildTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ArbitraryRebuildTest.php
@@ -18,7 +18,7 @@ class ArbitraryRebuildTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['text', 'form_test'];
+  protected static $modules = ['text', 'form_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Form/CheckboxTest.php b/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
index 60fad6a2e8..40eb6a4ae4 100644
--- a/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
+++ b/core/modules/system/tests/src/Functional/Form/CheckboxTest.php
@@ -17,7 +17,7 @@ class CheckboxTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   public function testFormCheckbox() {
     // Ensure that the checked state is determined and rendered correctly for
diff --git a/core/modules/system/tests/src/Functional/Form/ConfirmFormTest.php b/core/modules/system/tests/src/Functional/Form/ConfirmFormTest.php
index ad5a74b691..976031abf8 100644
--- a/core/modules/system/tests/src/Functional/Form/ConfirmFormTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ConfirmFormTest.php
@@ -18,7 +18,7 @@ class ConfirmFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   public function testConfirmForm() {
     // Test the building of the form.
diff --git a/core/modules/system/tests/src/Functional/Form/ElementTest.php b/core/modules/system/tests/src/Functional/Form/ElementTest.php
index 6eefa484bd..307bc05e3b 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementTest.php
@@ -16,7 +16,7 @@ class ElementTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests placeholder text for elements that support placeholders.
diff --git a/core/modules/system/tests/src/Functional/Form/ElementsAccessTest.php b/core/modules/system/tests/src/Functional/Form/ElementsAccessTest.php
index 1a92893c39..039ada39d9 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsAccessTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsAccessTest.php
@@ -16,7 +16,7 @@ class ElementsAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Ensures that child values are still processed when #access = FALSE.
diff --git a/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php b/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
index a7d404b86b..8a555d713f 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsContainerTest.php
@@ -16,7 +16,7 @@ class ElementsContainerTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests the #optional container property.
diff --git a/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php b/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php
index 91f3ec4a59..6fc9862a3b 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php
@@ -17,7 +17,7 @@ class ElementsLabelsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Test form elements, labels, title attributes and required marks output
diff --git a/core/modules/system/tests/src/Functional/Form/ElementsVerticalTabsTest.php b/core/modules/system/tests/src/Functional/Form/ElementsVerticalTabsTest.php
index 34ca1c9cf8..868c5c4464 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsVerticalTabsTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsVerticalTabsTest.php
@@ -18,7 +18,7 @@ class ElementsVerticalTabsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * A user with permission to access vertical_tab_test_tabs.
diff --git a/core/modules/system/tests/src/Functional/Form/EmailTest.php b/core/modules/system/tests/src/Functional/Form/EmailTest.php
index 2fe6ebe907..6468a36080 100644
--- a/core/modules/system/tests/src/Functional/Form/EmailTest.php
+++ b/core/modules/system/tests/src/Functional/Form/EmailTest.php
@@ -17,7 +17,7 @@ class EmailTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests that #type 'email' fields are properly validated.
diff --git a/core/modules/system/tests/src/Functional/Form/FormObjectTest.php b/core/modules/system/tests/src/Functional/Form/FormObjectTest.php
index e2c00f5d17..87a819b542 100644
--- a/core/modules/system/tests/src/Functional/Form/FormObjectTest.php
+++ b/core/modules/system/tests/src/Functional/Form/FormObjectTest.php
@@ -16,7 +16,7 @@ class FormObjectTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests using an object as the form callback.
diff --git a/core/modules/system/tests/src/Functional/Form/FormStoragePageCacheTest.php b/core/modules/system/tests/src/Functional/Form/FormStoragePageCacheTest.php
index 474a35b55a..c5d2357c5a 100644
--- a/core/modules/system/tests/src/Functional/Form/FormStoragePageCacheTest.php
+++ b/core/modules/system/tests/src/Functional/Form/FormStoragePageCacheTest.php
@@ -14,7 +14,7 @@ class FormStoragePageCacheTest extends BrowserTestBase {
   /**
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Form/FormTest.php b/core/modules/system/tests/src/Functional/Form/FormTest.php
index 2407a3f51a..4ec6ae9a9b 100644
--- a/core/modules/system/tests/src/Functional/Form/FormTest.php
+++ b/core/modules/system/tests/src/Functional/Form/FormTest.php
@@ -25,7 +25,7 @@ class FormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'form_test', 'file', 'datetime'];
+  protected static $modules = ['filter', 'form_test', 'file', 'datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php b/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
index 2262670f2b..d19bb5e5c7 100644
--- a/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
+++ b/core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
@@ -20,7 +20,7 @@ class LanguageSelectElementTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test', 'language'];
+  protected static $modules = ['form_test', 'language'];
 
   /**
    * Tests that the options printed by the language select element are correct.
diff --git a/core/modules/system/tests/src/Functional/Form/ModulesListFormWebTest.php b/core/modules/system/tests/src/Functional/Form/ModulesListFormWebTest.php
index dc63e64d72..7420ded71a 100644
--- a/core/modules/system/tests/src/Functional/Form/ModulesListFormWebTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ModulesListFormWebTest.php
@@ -14,7 +14,7 @@ class ModulesListFormWebTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system_test', 'help'];
+  protected static $modules = ['system_test', 'help'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Form/RedirectTest.php b/core/modules/system/tests/src/Functional/Form/RedirectTest.php
index 62253a681b..9909f51af1 100644
--- a/core/modules/system/tests/src/Functional/Form/RedirectTest.php
+++ b/core/modules/system/tests/src/Functional/Form/RedirectTest.php
@@ -16,7 +16,7 @@ class RedirectTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test', 'block'];
+  protected static $modules = ['form_test', 'block'];
 
   /**
    * Tests form redirection.
diff --git a/core/modules/system/tests/src/Functional/Form/ResponseTest.php b/core/modules/system/tests/src/Functional/Form/ResponseTest.php
index de5d8fd6c7..a043c46693 100644
--- a/core/modules/system/tests/src/Functional/Form/ResponseTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ResponseTest.php
@@ -17,7 +17,7 @@ class ResponseTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests that enforced responses propagate through subscribers and middleware.
diff --git a/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php b/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
index d30b4f110b..11746b6503 100644
--- a/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
+++ b/core/modules/system/tests/src/Functional/Form/StateValuesCleanAdvancedTest.php
@@ -23,7 +23,7 @@ class StateValuesCleanAdvancedTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'form_test'];
+  protected static $modules = ['file', 'form_test'];
 
   /**
    * An image file path for uploading.
diff --git a/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php b/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
index cae0835b5f..5049b0485c 100644
--- a/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
+++ b/core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
@@ -19,7 +19,7 @@ class StateValuesCleanTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests \Drupal\Core\Form\FormState::cleanValues().
diff --git a/core/modules/system/tests/src/Functional/Form/SystemConfigFormTest.php b/core/modules/system/tests/src/Functional/Form/SystemConfigFormTest.php
index 09ad06ac8c..c3304fb33a 100644
--- a/core/modules/system/tests/src/Functional/Form/SystemConfigFormTest.php
+++ b/core/modules/system/tests/src/Functional/Form/SystemConfigFormTest.php
@@ -16,7 +16,7 @@ class SystemConfigFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests the SystemConfigFormTestBase class.
diff --git a/core/modules/system/tests/src/Functional/Form/UrlTest.php b/core/modules/system/tests/src/Functional/Form/UrlTest.php
index 82d227bbdf..c4d2c61189 100644
--- a/core/modules/system/tests/src/Functional/Form/UrlTest.php
+++ b/core/modules/system/tests/src/Functional/Form/UrlTest.php
@@ -17,7 +17,7 @@ class UrlTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   protected $profile = 'testing';
 
diff --git a/core/modules/system/tests/src/Functional/Form/ValidationTest.php b/core/modules/system/tests/src/Functional/Form/ValidationTest.php
index 094a0af73c..799b2da751 100644
--- a/core/modules/system/tests/src/Functional/Form/ValidationTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ValidationTest.php
@@ -17,7 +17,7 @@ class ValidationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Tests #element_validate and #validate.
diff --git a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonAnonTest.php b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonAnonTest.php
index eb19bac6f1..040cbc98ef 100644
--- a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonAnonTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ActionHalJsonAnonTest extends ActionResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonBasicAuthTest.php b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonBasicAuthTest.php
index 7441f6ab4b..71ec8f0fed 100644
--- a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ActionHalJsonBasicAuthTest extends ActionResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonCookieTest.php b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonCookieTest.php
index f013032e85..5dbf181626 100644
--- a/core/modules/system/tests/src/Functional/Hal/ActionHalJsonCookieTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/ActionHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ActionHalJsonCookieTest extends ActionResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonAnonTest.php b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonAnonTest.php
index 0200624b16..4a95b9cc63 100644
--- a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonAnonTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class MenuHalJsonAnonTest extends MenuResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonBasicAuthTest.php b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonBasicAuthTest.php
index cce118b118..7c07b2867e 100644
--- a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class MenuHalJsonBasicAuthTest extends MenuResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonCookieTest.php b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonCookieTest.php
index 9f7346f259..a10b747525 100644
--- a/core/modules/system/tests/src/Functional/Hal/MenuHalJsonCookieTest.php
+++ b/core/modules/system/tests/src/Functional/Hal/MenuHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class MenuHalJsonCookieTest extends MenuResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Lock/LockFunctionalTest.php b/core/modules/system/tests/src/Functional/Lock/LockFunctionalTest.php
index 0b13f18d62..7af09ad671 100644
--- a/core/modules/system/tests/src/Functional/Lock/LockFunctionalTest.php
+++ b/core/modules/system/tests/src/Functional/Lock/LockFunctionalTest.php
@@ -16,7 +16,7 @@ class LockFunctionalTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   /**
    * Confirms that we can acquire and release locks in two parallel requests.
diff --git a/core/modules/system/tests/src/Functional/Mail/MailTest.php b/core/modules/system/tests/src/Functional/Mail/MailTest.php
index e8accddb6f..cae6343e36 100644
--- a/core/modules/system/tests/src/Functional/Mail/MailTest.php
+++ b/core/modules/system/tests/src/Functional/Mail/MailTest.php
@@ -19,7 +19,7 @@ class MailTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['simpletest', 'system_mail_failure_test'];
+  protected static $modules = ['simpletest', 'system_mail_failure_test'];
 
   /**
    * Assert that the pluggable mail system is functional.
diff --git a/core/modules/system/tests/src/Functional/Menu/BreadcrumbTest.php b/core/modules/system/tests/src/Functional/Menu/BreadcrumbTest.php
index 0e493e5d68..edcf385c03 100644
--- a/core/modules/system/tests/src/Functional/Menu/BreadcrumbTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/BreadcrumbTest.php
@@ -21,7 +21,7 @@ class BreadcrumbTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_test', 'block'];
+  protected static $modules = ['menu_test', 'block'];
 
   /**
    * An administrative user.
diff --git a/core/modules/system/tests/src/Functional/Menu/LocalActionTest.php b/core/modules/system/tests/src/Functional/Menu/LocalActionTest.php
index f7b9aafae4..2a78b118d5 100644
--- a/core/modules/system/tests/src/Functional/Menu/LocalActionTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/LocalActionTest.php
@@ -18,7 +18,7 @@ class LocalActionTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block', 'menu_test'];
+  protected static $modules = ['block', 'menu_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Menu/LocalTasksTest.php b/core/modules/system/tests/src/Functional/Menu/LocalTasksTest.php
index 1a49336777..824112cf94 100644
--- a/core/modules/system/tests/src/Functional/Menu/LocalTasksTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/LocalTasksTest.php
@@ -18,7 +18,7 @@ class LocalTasksTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block', 'menu_test', 'entity_test', 'node'];
+  protected static $modules = ['block', 'menu_test', 'entity_test', 'node'];
 
   /**
    * The local tasks block under testing.
diff --git a/core/modules/system/tests/src/Functional/Menu/MenuAccessTest.php b/core/modules/system/tests/src/Functional/Menu/MenuAccessTest.php
index 10af396a6d..2c95315d40 100644
--- a/core/modules/system/tests/src/Functional/Menu/MenuAccessTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/MenuAccessTest.php
@@ -17,7 +17,7 @@ class MenuAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'menu_test'];
+  protected static $modules = ['block', 'menu_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Menu/MenuLinkSecurityTest.php b/core/modules/system/tests/src/Functional/Menu/MenuLinkSecurityTest.php
index c58bf8e504..8432a676b1 100644
--- a/core/modules/system/tests/src/Functional/Menu/MenuLinkSecurityTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/MenuLinkSecurityTest.php
@@ -15,7 +15,7 @@ class MenuLinkSecurityTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'block', 'menu_test'];
+  protected static $modules = ['menu_link_content', 'block', 'menu_test'];
 
   /**
    * Ensures that a menu link does not cause an XSS issue.
diff --git a/core/modules/system/tests/src/Functional/Menu/MenuRouterTest.php b/core/modules/system/tests/src/Functional/Menu/MenuRouterTest.php
index 7669e1875a..e30eaef9a9 100644
--- a/core/modules/system/tests/src/Functional/Menu/MenuRouterTest.php
+++ b/core/modules/system/tests/src/Functional/Menu/MenuRouterTest.php
@@ -17,7 +17,7 @@ class MenuRouterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'menu_test', 'test_page_test'];
+  protected static $modules = ['block', 'menu_test', 'test_page_test'];
 
   /**
    * Name of the administrative theme to use for tests.
diff --git a/core/modules/system/tests/src/Functional/Module/InstallTest.php b/core/modules/system/tests/src/Functional/Module/InstallTest.php
index ccbca6d312..8026549863 100644
--- a/core/modules/system/tests/src/Functional/Module/InstallTest.php
+++ b/core/modules/system/tests/src/Functional/Module/InstallTest.php
@@ -17,7 +17,7 @@ class InstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['module_test'];
+  protected static $modules = ['module_test'];
 
   /**
    * Verify that drupal_get_schema() can be used during module installation.
diff --git a/core/modules/system/tests/src/Functional/Module/InstallUninstallTest.php b/core/modules/system/tests/src/Functional/Module/InstallUninstallTest.php
index 9ca4407801..ddd62a514a 100644
--- a/core/modules/system/tests/src/Functional/Module/InstallUninstallTest.php
+++ b/core/modules/system/tests/src/Functional/Module/InstallUninstallTest.php
@@ -16,7 +16,7 @@ class InstallUninstallTest extends ModuleTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system_test', 'dblog', 'taxonomy', 'update_test_postupdate'];
+  protected static $modules = ['system_test', 'dblog', 'taxonomy', 'update_test_postupdate'];
 
   /**
    * Tests that a fixed set of modules can be installed and uninstalled.
diff --git a/core/modules/system/tests/src/Functional/Module/ModuleTestBase.php b/core/modules/system/tests/src/Functional/Module/ModuleTestBase.php
index 6cc726326d..2d7bc6ef21 100644
--- a/core/modules/system/tests/src/Functional/Module/ModuleTestBase.php
+++ b/core/modules/system/tests/src/Functional/Module/ModuleTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/tests/src/Functional/Module/PrepareUninstallTest.php b/core/modules/system/tests/src/Functional/Module/PrepareUninstallTest.php
index 5edaf42afe..66e9e8214f 100644
--- a/core/modules/system/tests/src/Functional/Module/PrepareUninstallTest.php
+++ b/core/modules/system/tests/src/Functional/Module/PrepareUninstallTest.php
@@ -33,7 +33,7 @@ class PrepareUninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'taxonomy', 'entity_test'];
+  protected static $modules = ['node', 'taxonomy', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Module/UninstallTest.php b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
index 98b96ee91e..420443eaf9 100644
--- a/core/modules/system/tests/src/Functional/Module/UninstallTest.php
+++ b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
@@ -21,7 +21,7 @@ class UninstallTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['module_test', 'user', 'views', 'node'];
+  protected static $modules = ['module_test', 'user', 'views', 'node'];
 
   /**
    * Tests the hook_modules_uninstalled() of the user module.
diff --git a/core/modules/system/tests/src/Functional/ParamConverter/UpcastingTest.php b/core/modules/system/tests/src/Functional/ParamConverter/UpcastingTest.php
index faafe84600..404137aafa 100644
--- a/core/modules/system/tests/src/Functional/ParamConverter/UpcastingTest.php
+++ b/core/modules/system/tests/src/Functional/ParamConverter/UpcastingTest.php
@@ -12,7 +12,7 @@
  */
 class UpcastingTest extends BrowserTestBase {
 
-  public static $modules = ['paramconverter_test', 'node', 'language'];
+  protected static $modules = ['paramconverter_test', 'node', 'language'];
 
   /**
    * Confirms that all parameters are converted as expected.
diff --git a/core/modules/system/tests/src/Functional/Path/UrlAlterFunctionalTest.php b/core/modules/system/tests/src/Functional/Path/UrlAlterFunctionalTest.php
index 271774169f..3c1d7e380c 100644
--- a/core/modules/system/tests/src/Functional/Path/UrlAlterFunctionalTest.php
+++ b/core/modules/system/tests/src/Functional/Path/UrlAlterFunctionalTest.php
@@ -19,7 +19,7 @@ class UrlAlterFunctionalTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'forum', 'url_alter_test'];
+  protected static $modules = ['path', 'forum', 'url_alter_test'];
 
   /**
    * Test that URL altering works and that it occurs in the correct order.
diff --git a/core/modules/system/tests/src/Functional/Render/AjaxPageStateTest.php b/core/modules/system/tests/src/Functional/Render/AjaxPageStateTest.php
index 586b1c93b2..5cb34269b5 100644
--- a/core/modules/system/tests/src/Functional/Render/AjaxPageStateTest.php
+++ b/core/modules/system/tests/src/Functional/Render/AjaxPageStateTest.php
@@ -16,7 +16,7 @@ class AjaxPageStateTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views'];
+  protected static $modules = ['node', 'views'];
 
   /**
    * User account with all available permissions
diff --git a/core/modules/system/tests/src/Functional/Render/DisplayVariantTest.php b/core/modules/system/tests/src/Functional/Render/DisplayVariantTest.php
index 2f5415ba7c..47517ed41c 100644
--- a/core/modules/system/tests/src/Functional/Render/DisplayVariantTest.php
+++ b/core/modules/system/tests/src/Functional/Render/DisplayVariantTest.php
@@ -16,7 +16,7 @@ class DisplayVariantTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['display_variant_test'];
+  protected static $modules = ['display_variant_test'];
 
   /**
    * Tests selecting the variant and passing configuration.
diff --git a/core/modules/system/tests/src/Functional/Render/PlaceholderMessageTest.php b/core/modules/system/tests/src/Functional/Render/PlaceholderMessageTest.php
index 185ca4985a..0d7a1e9935 100644
--- a/core/modules/system/tests/src/Functional/Render/PlaceholderMessageTest.php
+++ b/core/modules/system/tests/src/Functional/Render/PlaceholderMessageTest.php
@@ -17,7 +17,7 @@ class PlaceholderMessageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['render_placeholder_message_test'];
+  protected static $modules = ['render_placeholder_message_test'];
 
   /**
    * Test rendering of message placeholder.
diff --git a/core/modules/system/tests/src/Functional/Render/RenderArrayNonHtmlSubscriberTest.php b/core/modules/system/tests/src/Functional/Render/RenderArrayNonHtmlSubscriberTest.php
index 08380dec02..08674b829e 100644
--- a/core/modules/system/tests/src/Functional/Render/RenderArrayNonHtmlSubscriberTest.php
+++ b/core/modules/system/tests/src/Functional/Render/RenderArrayNonHtmlSubscriberTest.php
@@ -17,7 +17,7 @@ class RenderArrayNonHtmlSubscriberTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['render_array_non_html_subscriber_test'];
+  protected static $modules = ['render_array_non_html_subscriber_test'];
 
   /**
    * Tests handling of responses by events subscriber.
diff --git a/core/modules/system/tests/src/Functional/Rest/ActionJsonBasicAuthTest.php b/core/modules/system/tests/src/Functional/Rest/ActionJsonBasicAuthTest.php
index fdc516b9e4..d5b887f8c5 100644
--- a/core/modules/system/tests/src/Functional/Rest/ActionJsonBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Rest/ActionJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ActionJsonBasicAuthTest extends ActionResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Rest/ActionResourceTestBase.php b/core/modules/system/tests/src/Functional/Rest/ActionResourceTestBase.php
index 5134e910a6..bfa9622591 100644
--- a/core/modules/system/tests/src/Functional/Rest/ActionResourceTestBase.php
+++ b/core/modules/system/tests/src/Functional/Rest/ActionResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Rest/ActionXmlBasicAuthTest.php b/core/modules/system/tests/src/Functional/Rest/ActionXmlBasicAuthTest.php
index f11459bc6d..9ea85939fe 100644
--- a/core/modules/system/tests/src/Functional/Rest/ActionXmlBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Rest/ActionXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ActionXmlBasicAuthTest extends ActionResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Rest/MenuJsonBasicAuthTest.php b/core/modules/system/tests/src/Functional/Rest/MenuJsonBasicAuthTest.php
index 1d35d42161..16f670d9cc 100644
--- a/core/modules/system/tests/src/Functional/Rest/MenuJsonBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Rest/MenuJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class MenuJsonBasicAuthTest extends MenuResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php b/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php
index 91953eb441..13a74beb3e 100644
--- a/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php
+++ b/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Rest/MenuXmlBasicAuthTest.php b/core/modules/system/tests/src/Functional/Rest/MenuXmlBasicAuthTest.php
index 0910430042..63ac36b260 100644
--- a/core/modules/system/tests/src/Functional/Rest/MenuXmlBasicAuthTest.php
+++ b/core/modules/system/tests/src/Functional/Rest/MenuXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class MenuXmlBasicAuthTest extends MenuResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Routing/RouterPermissionTest.php b/core/modules/system/tests/src/Functional/Routing/RouterPermissionTest.php
index 62a511f2e4..4071d84a1f 100644
--- a/core/modules/system/tests/src/Functional/Routing/RouterPermissionTest.php
+++ b/core/modules/system/tests/src/Functional/Routing/RouterPermissionTest.php
@@ -16,7 +16,7 @@ class RouterPermissionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test'];
+  protected static $modules = ['router_test'];
 
   /**
    * Tests permission requirements on routes.
diff --git a/core/modules/system/tests/src/Functional/ServiceProvider/ServiceProviderWebTest.php b/core/modules/system/tests/src/Functional/ServiceProvider/ServiceProviderWebTest.php
index 5e86164f6e..3bd4c03557 100644
--- a/core/modules/system/tests/src/Functional/ServiceProvider/ServiceProviderWebTest.php
+++ b/core/modules/system/tests/src/Functional/ServiceProvider/ServiceProviderWebTest.php
@@ -16,7 +16,7 @@ class ServiceProviderWebTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'service_provider_test'];
+  protected static $modules = ['file', 'service_provider_test'];
 
   /**
    * Tests that module service providers get registered to the DIC.
diff --git a/core/modules/system/tests/src/Functional/System/AccessDeniedTest.php b/core/modules/system/tests/src/Functional/System/AccessDeniedTest.php
index 6490910bee..d9f20144cb 100644
--- a/core/modules/system/tests/src/Functional/System/AccessDeniedTest.php
+++ b/core/modules/system/tests/src/Functional/System/AccessDeniedTest.php
@@ -21,7 +21,7 @@ class AccessDeniedTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'system_test'];
+  protected static $modules = ['block', 'node', 'system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/tests/src/Functional/System/AdminTest.php b/core/modules/system/tests/src/Functional/System/AdminTest.php
index 7a0b2a3ae6..ef30042270 100644
--- a/core/modules/system/tests/src/Functional/System/AdminTest.php
+++ b/core/modules/system/tests/src/Functional/System/AdminTest.php
@@ -31,7 +31,7 @@ class AdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   protected function setUp() {
     // testAdminPages() requires Locale module.
diff --git a/core/modules/system/tests/src/Functional/System/CronRunTest.php b/core/modules/system/tests/src/Functional/System/CronRunTest.php
index 12b86c83e7..54f06919fa 100644
--- a/core/modules/system/tests/src/Functional/System/CronRunTest.php
+++ b/core/modules/system/tests/src/Functional/System/CronRunTest.php
@@ -19,7 +19,7 @@ class CronRunTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['common_test', 'common_test_cron_helper', 'automated_cron'];
+  protected static $modules = ['common_test', 'common_test_cron_helper', 'automated_cron'];
 
   /**
    * Test cron runs.
diff --git a/core/modules/system/tests/src/Functional/System/DateTimeTest.php b/core/modules/system/tests/src/Functional/System/DateTimeTest.php
index bdecab5d4c..900ada6831 100644
--- a/core/modules/system/tests/src/Functional/System/DateTimeTest.php
+++ b/core/modules/system/tests/src/Functional/System/DateTimeTest.php
@@ -19,7 +19,7 @@ class DateTimeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'language', 'field', 'field_ui', 'datetime', 'options'];
+  protected static $modules = ['block', 'node', 'language', 'field', 'field_ui', 'datetime', 'options'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/System/FrontPageTest.php b/core/modules/system/tests/src/Functional/System/FrontPageTest.php
index 7f9fc8c1f0..6d5204b61f 100644
--- a/core/modules/system/tests/src/Functional/System/FrontPageTest.php
+++ b/core/modules/system/tests/src/Functional/System/FrontPageTest.php
@@ -17,7 +17,7 @@ class FrontPageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'system_test', 'views'];
+  protected static $modules = ['node', 'system_test', 'views'];
 
   /**
    * The path to a node that is created for testing.
diff --git a/core/modules/system/tests/src/Functional/System/HtaccessTest.php b/core/modules/system/tests/src/Functional/System/HtaccessTest.php
index 79c4766c4c..bd41b31f6f 100644
--- a/core/modules/system/tests/src/Functional/System/HtaccessTest.php
+++ b/core/modules/system/tests/src/Functional/System/HtaccessTest.php
@@ -16,7 +16,7 @@ class HtaccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   /**
    * Get an array of file paths for access testing.
diff --git a/core/modules/system/tests/src/Functional/System/MainContentFallbackTest.php b/core/modules/system/tests/src/Functional/System/MainContentFallbackTest.php
index 931b84ce24..d197d4a0c1 100644
--- a/core/modules/system/tests/src/Functional/System/MainContentFallbackTest.php
+++ b/core/modules/system/tests/src/Functional/System/MainContentFallbackTest.php
@@ -16,7 +16,7 @@ class MainContentFallbackTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'system_test'];
+  protected static $modules = ['block', 'system_test'];
 
   protected $adminUser;
   protected $webUser;
diff --git a/core/modules/system/tests/src/Functional/System/PageNotFoundTest.php b/core/modules/system/tests/src/Functional/System/PageNotFoundTest.php
index ab9b54b491..733125c4c8 100644
--- a/core/modules/system/tests/src/Functional/System/PageNotFoundTest.php
+++ b/core/modules/system/tests/src/Functional/System/PageNotFoundTest.php
@@ -21,7 +21,7 @@ class PageNotFoundTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/tests/src/Functional/System/PageTitleTest.php b/core/modules/system/tests/src/Functional/System/PageTitleTest.php
index 8073827fb2..53f07bf889 100644
--- a/core/modules/system/tests/src/Functional/System/PageTitleTest.php
+++ b/core/modules/system/tests/src/Functional/System/PageTitleTest.php
@@ -19,7 +19,7 @@ class PageTitleTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'test_page_test', 'form_test', 'block'];
+  protected static $modules = ['node', 'test_page_test', 'form_test', 'block'];
 
   protected $contentUser;
   protected $savedTitle;
diff --git a/core/modules/system/tests/src/Functional/System/ResponseGeneratorTest.php b/core/modules/system/tests/src/Functional/System/ResponseGeneratorTest.php
index 592364636d..34013d9412 100644
--- a/core/modules/system/tests/src/Functional/System/ResponseGeneratorTest.php
+++ b/core/modules/system/tests/src/Functional/System/ResponseGeneratorTest.php
@@ -17,7 +17,7 @@ class ResponseGeneratorTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal', 'rest', 'node', 'basic_auth'];
+  protected static $modules = ['hal', 'rest', 'node', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/System/ShutdownFunctionsTest.php b/core/modules/system/tests/src/Functional/System/ShutdownFunctionsTest.php
index 0859ebd355..802b9d3fa6 100644
--- a/core/modules/system/tests/src/Functional/System/ShutdownFunctionsTest.php
+++ b/core/modules/system/tests/src/Functional/System/ShutdownFunctionsTest.php
@@ -16,7 +16,7 @@ class ShutdownFunctionsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected function tearDown() {
     // This test intentionally throws an exception in a PHP shutdown function.
diff --git a/core/modules/system/tests/src/Functional/System/SiteMaintenanceTest.php b/core/modules/system/tests/src/Functional/System/SiteMaintenanceTest.php
index 389b3f7566..eb6202b8ce 100644
--- a/core/modules/system/tests/src/Functional/System/SiteMaintenanceTest.php
+++ b/core/modules/system/tests/src/Functional/System/SiteMaintenanceTest.php
@@ -22,7 +22,7 @@ class SiteMaintenanceTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/tests/src/Functional/System/StatusTest.php b/core/modules/system/tests/src/Functional/System/StatusTest.php
index c902a3731f..9c99cec069 100644
--- a/core/modules/system/tests/src/Functional/System/StatusTest.php
+++ b/core/modules/system/tests/src/Functional/System/StatusTest.php
@@ -17,7 +17,7 @@ class StatusTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['update_test_postupdate'];
+  protected static $modules = ['update_test_postupdate'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/System/SystemAuthorizeTest.php b/core/modules/system/tests/src/Functional/System/SystemAuthorizeTest.php
index b3f9b310b3..42af534038 100644
--- a/core/modules/system/tests/src/Functional/System/SystemAuthorizeTest.php
+++ b/core/modules/system/tests/src/Functional/System/SystemAuthorizeTest.php
@@ -16,7 +16,7 @@ class SystemAuthorizeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/System/ThemeTest.php b/core/modules/system/tests/src/Functional/System/ThemeTest.php
index d1d7880c8f..81377d0a22 100644
--- a/core/modules/system/tests/src/Functional/System/ThemeTest.php
+++ b/core/modules/system/tests/src/Functional/System/ThemeTest.php
@@ -30,7 +30,7 @@ class ThemeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'file'];
+  protected static $modules = ['node', 'block', 'file'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/System/TokenReplaceWebTest.php b/core/modules/system/tests/src/Functional/System/TokenReplaceWebTest.php
index 450f507045..3c889e8acf 100644
--- a/core/modules/system/tests/src/Functional/System/TokenReplaceWebTest.php
+++ b/core/modules/system/tests/src/Functional/System/TokenReplaceWebTest.php
@@ -18,7 +18,7 @@ class TokenReplaceWebTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['token_test', 'filter', 'node'];
+  protected static $modules = ['token_test', 'filter', 'node'];
 
   /**
    * Tests a token replacement on an actual website.
diff --git a/core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php b/core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php
index 6dca1b38d3..0f0c3ef466 100644
--- a/core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php
@@ -16,7 +16,7 @@ class EngineNyanCatTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Theme/EngineTwigTest.php b/core/modules/system/tests/src/Functional/Theme/EngineTwigTest.php
index 07b30ee30f..8e3e2b43aa 100644
--- a/core/modules/system/tests/src/Functional/Theme/EngineTwigTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/EngineTwigTest.php
@@ -21,7 +21,7 @@ class EngineTwigTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test', 'twig_theme_test'];
+  protected static $modules = ['theme_test', 'twig_theme_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Theme/FastTest.php b/core/modules/system/tests/src/Functional/Theme/FastTest.php
index d8f85f1f4a..188b236168 100644
--- a/core/modules/system/tests/src/Functional/Theme/FastTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/FastTest.php
@@ -16,7 +16,7 @@ class FastTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Theme/HtmlAttributesTest.php b/core/modules/system/tests/src/Functional/Theme/HtmlAttributesTest.php
index 5aa4be9cc9..4645526ad6 100644
--- a/core/modules/system/tests/src/Functional/Theme/HtmlAttributesTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/HtmlAttributesTest.php
@@ -16,7 +16,7 @@ class HtmlAttributesTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   /**
    * Tests that attributes in the 'html' and 'body' elements can be altered.
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
index 040dfabfce..c955628614 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
@@ -17,7 +17,7 @@ class ThemeEarlyInitializationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   /**
    * Test that the theme system can generate output in a request listener.
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeInfoTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeInfoTest.php
index e372bb262a..5aa164277a 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeInfoTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeInfoTest.php
@@ -16,7 +16,7 @@ class ThemeInfoTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   /**
    * The theme handler used in this test for enabling themes.
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php
index 5f2668ef0a..ef399cb748 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php
@@ -17,7 +17,7 @@ class ThemeSuggestionsAlterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeTest.php
index fff7bdfa4e..edfce700f2 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeTest.php
@@ -18,7 +18,7 @@ class ThemeTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['theme_test', 'node'];
+  protected static $modules = ['theme_test', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
index 1488c5b3e4..4ecfb10b0d 100644
--- a/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/ThemeTokenTest.php
@@ -16,7 +16,7 @@ class ThemeTokenTest extends BrowserTestBase {
    *
    * @var array
    */
-  static public $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigDebugMarkupTest.php b/core/modules/system/tests/src/Functional/Theme/TwigDebugMarkupTest.php
index 9fe89fd58b..92c5a4701a 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigDebugMarkupTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigDebugMarkupTest.php
@@ -17,7 +17,7 @@ class TwigDebugMarkupTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test', 'node'];
+  protected static $modules = ['theme_test', 'node'];
 
   /**
    * Tests debug markup added to Twig template output.
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php b/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
index 588b947e6e..a59c8189c6 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
@@ -17,7 +17,7 @@ class TwigExtensionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test', 'twig_extension_test'];
+  protected static $modules = ['theme_test', 'twig_extension_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigLoaderTest.php b/core/modules/system/tests/src/Functional/Theme/TwigLoaderTest.php
index d2b0b5465d..af7bea32c5 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigLoaderTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigLoaderTest.php
@@ -16,7 +16,7 @@ class TwigLoaderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_loader_test'];
+  protected static $modules = ['twig_loader_test'];
 
   /**
    * Tests adding an additional twig loader to the loader chain.
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigRegistryLoaderTest.php b/core/modules/system/tests/src/Functional/Theme/TwigRegistryLoaderTest.php
index 2446289984..d6cd472e61 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigRegistryLoaderTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigRegistryLoaderTest.php
@@ -16,7 +16,7 @@ class TwigRegistryLoaderTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_theme_test', 'block'];
+  protected static $modules = ['twig_theme_test', 'block'];
 
   /**
    * @var \Drupal\Core\Template\TwigEnvironment
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigSettingsTest.php b/core/modules/system/tests/src/Functional/Theme/TwigSettingsTest.php
index fd759502e3..c980e18b45 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigSettingsTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigSettingsTest.php
@@ -17,7 +17,7 @@ class TwigSettingsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   /**
    * Ensures Twig template auto reload setting can be overridden.
diff --git a/core/modules/system/tests/src/Functional/Theme/TwigTransTest.php b/core/modules/system/tests/src/Functional/Theme/TwigTransTest.php
index aeafe7aeb1..dba1b78241 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigTransTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigTransTest.php
@@ -17,7 +17,7 @@ class TwigTransTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'theme_test',
     'twig_theme_test',
     'locale',
diff --git a/core/modules/system/tests/src/Functional/Update/DependencyHookInvocationTest.php b/core/modules/system/tests/src/Functional/Update/DependencyHookInvocationTest.php
index 203d89ef2a..d6be777acc 100644
--- a/core/modules/system/tests/src/Functional/Update/DependencyHookInvocationTest.php
+++ b/core/modules/system/tests/src/Functional/Update/DependencyHookInvocationTest.php
@@ -17,7 +17,7 @@ class DependencyHookInvocationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test_0', 'update_test_1', 'update_test_2'];
+  protected static $modules = ['update_test_0', 'update_test_1', 'update_test_2'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Update/DependencyMissingTest.php b/core/modules/system/tests/src/Functional/Update/DependencyMissingTest.php
index e11999a46c..b01b82dcc0 100644
--- a/core/modules/system/tests/src/Functional/Update/DependencyMissingTest.php
+++ b/core/modules/system/tests/src/Functional/Update/DependencyMissingTest.php
@@ -16,7 +16,7 @@ class DependencyMissingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test_0', 'update_test_2'];
+  protected static $modules = ['update_test_0', 'update_test_2'];
 
   protected function setUp() {
     // Only install update_test_2.module, even though its updates have a
diff --git a/core/modules/system/tests/src/Functional/Update/DependencyOrderingTest.php b/core/modules/system/tests/src/Functional/Update/DependencyOrderingTest.php
index 0f168aa78f..1946b8d888 100644
--- a/core/modules/system/tests/src/Functional/Update/DependencyOrderingTest.php
+++ b/core/modules/system/tests/src/Functional/Update/DependencyOrderingTest.php
@@ -16,7 +16,7 @@ class DependencyOrderingTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test_0', 'update_test_1', 'update_test_2', 'update_test_3'];
+  protected static $modules = ['update_test_0', 'update_test_1', 'update_test_2', 'update_test_3'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Update/InvalidUpdateHookTest.php b/core/modules/system/tests/src/Functional/Update/InvalidUpdateHookTest.php
index 85d041e2a4..573be5cbd8 100644
--- a/core/modules/system/tests/src/Functional/Update/InvalidUpdateHookTest.php
+++ b/core/modules/system/tests/src/Functional/Update/InvalidUpdateHookTest.php
@@ -17,7 +17,7 @@ class InvalidUpdateHookTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test_invalid_hook', 'update_script_test', 'dblog'];
+  protected static $modules = ['update_test_invalid_hook', 'update_script_test', 'dblog'];
 
   /**
    * URL for the upgrade script.
diff --git a/core/modules/system/tests/src/Functional/Update/UpdateSchemaTest.php b/core/modules/system/tests/src/Functional/Update/UpdateSchemaTest.php
index 1c2edee065..b1e600922b 100644
--- a/core/modules/system/tests/src/Functional/Update/UpdateSchemaTest.php
+++ b/core/modules/system/tests/src/Functional/Update/UpdateSchemaTest.php
@@ -15,7 +15,7 @@ class UpdateSchemaTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['update_test_schema'];
+  protected static $modules = ['update_test_schema'];
 
   /**
    * @var \Drupal\user\UserInterface
diff --git a/core/modules/system/tests/src/Functional/Update/UpdateScriptTest.php b/core/modules/system/tests/src/Functional/Update/UpdateScriptTest.php
index 29d4d08e23..b723a0980f 100644
--- a/core/modules/system/tests/src/Functional/Update/UpdateScriptTest.php
+++ b/core/modules/system/tests/src/Functional/Update/UpdateScriptTest.php
@@ -18,7 +18,7 @@ class UpdateScriptTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_script_test', 'dblog', 'language'];
+  protected static $modules = ['update_script_test', 'dblog', 'language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Update/UpdatesWith7xTest.php b/core/modules/system/tests/src/Functional/Update/UpdatesWith7xTest.php
index 4f536ea5aa..686ce4f51d 100644
--- a/core/modules/system/tests/src/Functional/Update/UpdatesWith7xTest.php
+++ b/core/modules/system/tests/src/Functional/Update/UpdatesWith7xTest.php
@@ -17,7 +17,7 @@ class UpdatesWith7xTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test_with_7x'];
+  protected static $modules = ['update_test_with_7x'];
 
   /**
    * The URL for the update page.
diff --git a/core/modules/system/tests/src/FunctionalJavascript/ModalRendererTest.php b/core/modules/system/tests/src/FunctionalJavascript/ModalRendererTest.php
index 3597ba46dd..e4ec16bfe8 100644
--- a/core/modules/system/tests/src/FunctionalJavascript/ModalRendererTest.php
+++ b/core/modules/system/tests/src/FunctionalJavascript/ModalRendererTest.php
@@ -14,7 +14,7 @@ class ModalRendererTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'dialog_renderer_test'];
+  protected static $modules = ['system', 'dialog_renderer_test'];
 
   /**
    * Tests that links respect 'data-dialog-renderer' attribute.
diff --git a/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php b/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php
index c42d777c13..4537af0dd7 100644
--- a/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php
+++ b/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php
@@ -21,7 +21,7 @@ class OffCanvasTest extends OffCanvasTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'off_canvas_test',
   ];
 
diff --git a/core/modules/system/tests/src/FunctionalJavascript/ThemeFormSettingsTest.php b/core/modules/system/tests/src/FunctionalJavascript/ThemeFormSettingsTest.php
index 4f3e9f1d49..e524d24518 100644
--- a/core/modules/system/tests/src/FunctionalJavascript/ThemeFormSettingsTest.php
+++ b/core/modules/system/tests/src/FunctionalJavascript/ThemeFormSettingsTest.php
@@ -18,7 +18,7 @@ class ThemeFormSettingsTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Action/ActionTest.php b/core/modules/system/tests/src/Kernel/Action/ActionTest.php
index 6c381d7c80..6a2c7c6120 100644
--- a/core/modules/system/tests/src/Kernel/Action/ActionTest.php
+++ b/core/modules/system/tests/src/Kernel/Action/ActionTest.php
@@ -17,7 +17,7 @@ class ActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'field', 'user', 'action_test'];
+  protected static $modules = ['system', 'field', 'user', 'action_test'];
 
   /**
    * The action manager.
diff --git a/core/modules/system/tests/src/Kernel/Block/SystemMenuBlockTest.php b/core/modules/system/tests/src/Kernel/Block/SystemMenuBlockTest.php
index 7a6d6685e9..d1a890cbd4 100644
--- a/core/modules/system/tests/src/Kernel/Block/SystemMenuBlockTest.php
+++ b/core/modules/system/tests/src/Kernel/Block/SystemMenuBlockTest.php
@@ -31,7 +31,7 @@ class SystemMenuBlockTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'block',
     'menu_test',
diff --git a/core/modules/system/tests/src/Kernel/Common/AddFeedTest.php b/core/modules/system/tests/src/Kernel/Common/AddFeedTest.php
index 1060b30e4a..324e6f6709 100644
--- a/core/modules/system/tests/src/Kernel/Common/AddFeedTest.php
+++ b/core/modules/system/tests/src/Kernel/Common/AddFeedTest.php
@@ -15,7 +15,7 @@ class AddFeedTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests attaching feeds with paths, URLs, and titles.
diff --git a/core/modules/system/tests/src/Kernel/DateFormatAccessControlHandlerTest.php b/core/modules/system/tests/src/Kernel/DateFormatAccessControlHandlerTest.php
index 01b09dc6bb..d5767ed579 100644
--- a/core/modules/system/tests/src/Kernel/DateFormatAccessControlHandlerTest.php
+++ b/core/modules/system/tests/src/Kernel/DateFormatAccessControlHandlerTest.php
@@ -24,7 +24,7 @@ class DateFormatAccessControlHandlerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
   ];
diff --git a/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php b/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php
index 058f83bb93..33c68cfbce 100644
--- a/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php
+++ b/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php
@@ -41,7 +41,7 @@ class EntityReferenceSelectionReferenceableTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'field', 'entity_reference', 'node', 'entity_test'];
+  protected static $modules = ['system', 'user', 'field', 'entity_reference', 'node', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php b/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
index 708d517a32..0eee3185da 100644
--- a/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
+++ b/core/modules/system/tests/src/Kernel/Extension/ModuleHandlerTest.php
@@ -17,7 +17,7 @@ class ModuleHandlerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Form/FormElementLabelTest.php b/core/modules/system/tests/src/Kernel/Form/FormElementLabelTest.php
index 2bc895f8a0..5a7992c496 100644
--- a/core/modules/system/tests/src/Kernel/Form/FormElementLabelTest.php
+++ b/core/modules/system/tests/src/Kernel/Form/FormElementLabelTest.php
@@ -15,7 +15,7 @@ class FormElementLabelTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Ensures that attributes can be placed for form element label.
diff --git a/core/modules/system/tests/src/Kernel/Form/FormElementMaxlengthTest.php b/core/modules/system/tests/src/Kernel/Form/FormElementMaxlengthTest.php
index 94026b6541..480ccb3b30 100644
--- a/core/modules/system/tests/src/Kernel/Form/FormElementMaxlengthTest.php
+++ b/core/modules/system/tests/src/Kernel/Form/FormElementMaxlengthTest.php
@@ -18,7 +18,7 @@ class FormElementMaxlengthTest extends KernelTestBase implements FormInterface {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Form/FormObjectTest.php b/core/modules/system/tests/src/Kernel/Form/FormObjectTest.php
index 36cbb50ca7..730d1ae4c2 100644
--- a/core/modules/system/tests/src/Kernel/Form/FormObjectTest.php
+++ b/core/modules/system/tests/src/Kernel/Form/FormObjectTest.php
@@ -17,7 +17,7 @@ class FormObjectTest extends ConfigFormTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Kernel/Form/ProgrammaticTest.php b/core/modules/system/tests/src/Kernel/Form/ProgrammaticTest.php
index 28d056cecd..58fa338c4f 100644
--- a/core/modules/system/tests/src/Kernel/Form/ProgrammaticTest.php
+++ b/core/modules/system/tests/src/Kernel/Form/ProgrammaticTest.php
@@ -17,7 +17,7 @@ class ProgrammaticTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * Test the programmatic form submission workflow.
diff --git a/core/modules/system/tests/src/Kernel/Installer/InstallerMissingDependenciesTest.php b/core/modules/system/tests/src/Kernel/Installer/InstallerMissingDependenciesTest.php
index 052c0afb80..226c5dc426 100644
--- a/core/modules/system/tests/src/Kernel/Installer/InstallerMissingDependenciesTest.php
+++ b/core/modules/system/tests/src/Kernel/Installer/InstallerMissingDependenciesTest.php
@@ -14,7 +14,7 @@ class InstallerMissingDependenciesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Verifies that the exception message in the profile step is correct.
diff --git a/core/modules/system/tests/src/Kernel/Installer/UninstallKernelTest.php b/core/modules/system/tests/src/Kernel/Installer/UninstallKernelTest.php
index f3591538c8..cc94bc2b5a 100644
--- a/core/modules/system/tests/src/Kernel/Installer/UninstallKernelTest.php
+++ b/core/modules/system/tests/src/Kernel/Installer/UninstallKernelTest.php
@@ -16,7 +16,7 @@ class UninstallKernelTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'file', 'image', 'media'];
+  protected static $modules = ['system', 'user', 'field', 'file', 'image', 'media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/MenuAccessControlHandlerTest.php b/core/modules/system/tests/src/Kernel/MenuAccessControlHandlerTest.php
index 6d702c7cb5..9291db94f3 100644
--- a/core/modules/system/tests/src/Kernel/MenuAccessControlHandlerTest.php
+++ b/core/modules/system/tests/src/Kernel/MenuAccessControlHandlerTest.php
@@ -24,7 +24,7 @@ class MenuAccessControlHandlerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
   ];
diff --git a/core/modules/system/tests/src/Kernel/Migrate/d6/MigrateSystemConfigurationTest.php b/core/modules/system/tests/src/Kernel/Migrate/d6/MigrateSystemConfigurationTest.php
index 33c963de3c..c5181de13e 100644
--- a/core/modules/system/tests/src/Kernel/Migrate/d6/MigrateSystemConfigurationTest.php
+++ b/core/modules/system/tests/src/Kernel/Migrate/d6/MigrateSystemConfigurationTest.php
@@ -14,7 +14,7 @@ class MigrateSystemConfigurationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['action', 'file', 'system'];
+  protected static $modules = ['action', 'file', 'system'];
 
   protected $expectedConfig = [
     'system.cron' => [
diff --git a/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateGlobalThemeSettingsTest.php b/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateGlobalThemeSettingsTest.php
index 56ee5b6312..73bfef93e1 100644
--- a/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateGlobalThemeSettingsTest.php
+++ b/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateGlobalThemeSettingsTest.php
@@ -14,7 +14,7 @@ class MigrateGlobalThemeSettingsTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateSystemConfigurationTest.php b/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateSystemConfigurationTest.php
index 0216e2dd31..dd933317b9 100644
--- a/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateSystemConfigurationTest.php
+++ b/core/modules/system/tests/src/Kernel/Migrate/d7/MigrateSystemConfigurationTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateSystemConfigurationTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['action', 'file', 'system'];
+  protected static $modules = ['action', 'file', 'system'];
 
   protected $expectedConfig = [
     'system.authorize' => [
diff --git a/core/modules/system/tests/src/Kernel/PathHooksTest.php b/core/modules/system/tests/src/Kernel/PathHooksTest.php
index fcbb499979..497610e3e9 100644
--- a/core/modules/system/tests/src/Kernel/PathHooksTest.php
+++ b/core/modules/system/tests/src/Kernel/PathHooksTest.php
@@ -15,7 +15,7 @@ class PathHooksTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  static public $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Test system_path_*() correctly clears caches.
diff --git a/core/modules/system/tests/src/Kernel/PermissionsTest.php b/core/modules/system/tests/src/Kernel/PermissionsTest.php
index fdd69f52f5..b423ddb4be 100644
--- a/core/modules/system/tests/src/Kernel/PermissionsTest.php
+++ b/core/modules/system/tests/src/Kernel/PermissionsTest.php
@@ -12,7 +12,7 @@ class PermissionsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
   ];
diff --git a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/ExtensionTest.php b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/ExtensionTest.php
index c6576019a7..64251b7107 100644
--- a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/ExtensionTest.php
+++ b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/ExtensionTest.php
@@ -15,7 +15,7 @@ class ExtensionTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'migrate_drupal'];
+  protected static $modules = ['system', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/MenuTest.php b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/MenuTest.php
index 0feb9a2b0f..3917b37cc0 100644
--- a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/MenuTest.php
+++ b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/MenuTest.php
@@ -16,7 +16,7 @@ class MenuTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'migrate_drupal'];
+  protected static $modules = ['system', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
index 17b54fa1bc..482e4ddf68 100644
--- a/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
+++ b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/d7/ThemeSettingsTest.php
@@ -16,7 +16,7 @@ class ThemeSettingsTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'migrate_drupal'];
+  protected static $modules = ['system', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Render/ClassyTest.php b/core/modules/system/tests/src/Kernel/Render/ClassyTest.php
index 8d1cb85481..4708503f2f 100644
--- a/core/modules/system/tests/src/Kernel/Render/ClassyTest.php
+++ b/core/modules/system/tests/src/Kernel/Render/ClassyTest.php
@@ -14,7 +14,7 @@ class ClassyTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'twig_theme_test'];
+  protected static $modules = ['system', 'twig_theme_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Scripts/DbDumpCommandTest.php b/core/modules/system/tests/src/Kernel/Scripts/DbDumpCommandTest.php
index a2ca864862..3e6ec4c86c 100644
--- a/core/modules/system/tests/src/Kernel/Scripts/DbDumpCommandTest.php
+++ b/core/modules/system/tests/src/Kernel/Scripts/DbDumpCommandTest.php
@@ -17,7 +17,7 @@ class DbDumpCommandTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Scripts/DbImportCommandTest.php b/core/modules/system/tests/src/Kernel/Scripts/DbImportCommandTest.php
index 8a292e502d..e489371db8 100644
--- a/core/modules/system/tests/src/Kernel/Scripts/DbImportCommandTest.php
+++ b/core/modules/system/tests/src/Kernel/Scripts/DbImportCommandTest.php
@@ -17,7 +17,7 @@ class DbImportCommandTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'config', 'dblog', 'menu_link_content', 'link', 'block_content', 'file', 'user'];
+  protected static $modules = ['system', 'config', 'dblog', 'menu_link_content', 'link', 'block_content', 'file', 'user'];
 
   /**
    * Tables that should be part of the exported script.
diff --git a/core/modules/system/tests/src/Kernel/System/CronQueueTest.php b/core/modules/system/tests/src/Kernel/System/CronQueueTest.php
index 649a2c7526..f5e13bfe84 100644
--- a/core/modules/system/tests/src/Kernel/System/CronQueueTest.php
+++ b/core/modules/system/tests/src/Kernel/System/CronQueueTest.php
@@ -17,7 +17,7 @@ class CronQueueTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'cron_queue_test'];
+  protected static $modules = ['system', 'cron_queue_test'];
 
   /**
    * The database connection.
diff --git a/core/modules/system/tests/src/Kernel/System/InfoAlterTest.php b/core/modules/system/tests/src/Kernel/System/InfoAlterTest.php
index ebdac3ce0d..3c64d29e6f 100644
--- a/core/modules/system/tests/src/Kernel/System/InfoAlterTest.php
+++ b/core/modules/system/tests/src/Kernel/System/InfoAlterTest.php
@@ -11,7 +11,7 @@
  */
 class InfoAlterTest extends KernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests that theme .info.yml data is rebuild after enabling a module.
diff --git a/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php b/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
index cd42fa4870..e2d79b944d 100644
--- a/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
+++ b/core/modules/system/tests/src/Kernel/System/SystemGetInfoTest.php
@@ -11,7 +11,7 @@
  */
 class SystemGetInfoTest extends KernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests system_get_info().
diff --git a/core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php b/core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
index 9b93dff3ff..0d72e4b31a 100644
--- a/core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
+++ b/core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
@@ -21,7 +21,7 @@ class FunctionsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test', 'system'];
+  protected static $modules = ['router_test', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Theme/ThemeTest.php b/core/modules/system/tests/src/Kernel/Theme/ThemeTest.php
index b9f09ec034..05281901aa 100644
--- a/core/modules/system/tests/src/Kernel/Theme/ThemeTest.php
+++ b/core/modules/system/tests/src/Kernel/Theme/ThemeTest.php
@@ -16,7 +16,7 @@ class ThemeTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['theme_test', 'node', 'system'];
+  protected static $modules = ['theme_test', 'node', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Kernel/Theme/TwigFilterTest.php b/core/modules/system/tests/src/Kernel/Theme/TwigFilterTest.php
index c1c26dd032..c32911ee83 100644
--- a/core/modules/system/tests/src/Kernel/Theme/TwigFilterTest.php
+++ b/core/modules/system/tests/src/Kernel/Theme/TwigFilterTest.php
@@ -16,7 +16,7 @@ class TwigFilterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_theme_test'];
+  protected static $modules = ['twig_theme_test'];
 
   /**
    * Test Twig "without" filter.
diff --git a/core/modules/system/tests/src/Kernel/Theme/TwigNamespaceTest.php b/core/modules/system/tests/src/Kernel/Theme/TwigNamespaceTest.php
index 4ffd2558f0..123afb1a62 100644
--- a/core/modules/system/tests/src/Kernel/Theme/TwigNamespaceTest.php
+++ b/core/modules/system/tests/src/Kernel/Theme/TwigNamespaceTest.php
@@ -16,7 +16,7 @@ class TwigNamespaceTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_theme_test', 'twig_namespace_a', 'twig_namespace_b', 'node'];
+  protected static $modules = ['twig_theme_test', 'twig_namespace_a', 'twig_namespace_b', 'node'];
 
   /**
    * @var \Drupal\Core\Template\TwigEnvironment
diff --git a/core/modules/system/tests/src/Kernel/Theme/TwigRawTest.php b/core/modules/system/tests/src/Kernel/Theme/TwigRawTest.php
index 970e9d5140..5af515115b 100644
--- a/core/modules/system/tests/src/Kernel/Theme/TwigRawTest.php
+++ b/core/modules/system/tests/src/Kernel/Theme/TwigRawTest.php
@@ -16,7 +16,7 @@ class TwigRawTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_theme_test'];
+  protected static $modules = ['twig_theme_test'];
 
   /**
    * Tests the raw filter inside an autoescape tag.
diff --git a/core/modules/system/tests/src/Kernel/Timezone/TimezoneTest.php b/core/modules/system/tests/src/Kernel/Timezone/TimezoneTest.php
index 8a5385c2fe..42ff81c281 100644
--- a/core/modules/system/tests/src/Kernel/Timezone/TimezoneTest.php
+++ b/core/modules/system/tests/src/Kernel/Timezone/TimezoneTest.php
@@ -11,7 +11,7 @@
  */
 class TimezoneTest extends KernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests system_time_zones().
diff --git a/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
index 2c83390604..3ebf352397 100644
--- a/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
+++ b/core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTestBase.php
@@ -28,7 +28,7 @@
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/src/Tests/RssTest.php b/core/modules/taxonomy/src/Tests/RssTest.php
index c4f48846b4..5aa212cfa0 100644
--- a/core/modules/taxonomy/src/Tests/RssTest.php
+++ b/core/modules/taxonomy/src/Tests/RssTest.php
@@ -18,7 +18,7 @@ class RssTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_ui', 'views'];
+  protected static $modules = ['node', 'field_ui', 'views'];
 
   /**
    * Vocabulary for testing.
diff --git a/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
index 599b6fb2c7..6701e53cc4 100644
--- a/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
+++ b/core/modules/taxonomy/src/Tests/TaxonomyTermIndentationTest.php
@@ -14,7 +14,7 @@ class TaxonomyTermIndentationTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Vocabulary for testing.
diff --git a/core/modules/taxonomy/src/Tests/TaxonomyTestBase.php b/core/modules/taxonomy/src/Tests/TaxonomyTestBase.php
index b4f941da5b..4ca7868f7b 100644
--- a/core/modules/taxonomy/src/Tests/TaxonomyTestBase.php
+++ b/core/modules/taxonomy/src/Tests/TaxonomyTestBase.php
@@ -24,7 +24,7 @@
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'block'];
+  protected static $modules = ['taxonomy', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/src/Tests/TermTest.php b/core/modules/taxonomy/src/Tests/TermTest.php
index 54309c4237..e408adfe25 100644
--- a/core/modules/taxonomy/src/Tests/TermTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTest.php
@@ -34,7 +34,7 @@ class TermTest extends TaxonomyTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/src/Tests/TermTranslationTest.php b/core/modules/taxonomy/src/Tests/TermTranslationTest.php
index ccb16f611d..8e32362a8a 100644
--- a/core/modules/taxonomy/src/Tests/TermTranslationTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTranslationTest.php
@@ -36,7 +36,7 @@ class TermTranslationTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'language', 'content_translation'];
+  protected static $modules = ['taxonomy', 'language', 'content_translation'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/EarlyDateTest.php b/core/modules/taxonomy/tests/src/Functional/EarlyDateTest.php
index e4490f3431..0132ab7265 100644
--- a/core/modules/taxonomy/tests/src/Functional/EarlyDateTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/EarlyDateTest.php
@@ -18,7 +18,7 @@ class EarlyDateTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'datetime'];
+  protected static $modules = ['node', 'datetime'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonAnonTest.php b/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonAnonTest.php
index ee3effc572..4544f70d9b 100644
--- a/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonAnonTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class TermHalJsonAnonTest extends TermResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonBasicAuthTest.php
index 5766156072..574c68f0f6 100644
--- a/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Hal/TermHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class TermHalJsonBasicAuthTest extends TermHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonAnonTest.php b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonAnonTest.php
index e2c1bc86bd..9ab5e23cc5 100644
--- a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonAnonTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class VocabularyHalJsonAnonTest extends VocabularyResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonBasicAuthTest.php
index d8c17e6d3a..cf105d0bd2 100644
--- a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class VocabularyHalJsonBasicAuthTest extends VocabularyResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonCookieTest.php b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonCookieTest.php
index 13a44dbb93..dfa861cfd2 100644
--- a/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonCookieTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Hal/VocabularyHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class VocabularyHalJsonCookieTest extends VocabularyResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/TermJsonBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Rest/TermJsonBasicAuthTest.php
index 959e2bb187..21ef548de0 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/TermJsonBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/TermJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class TermJsonBasicAuthTest extends TermResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/TermResourceTestBase.php b/core/modules/taxonomy/tests/src/Functional/Rest/TermResourceTestBase.php
index 3a1a5a241d..681cef374d 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/TermResourceTestBase.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/TermResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'path'];
+  protected static $modules = ['taxonomy', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/TermXmlBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Rest/TermXmlBasicAuthTest.php
index 8eacb85c1c..97abbc7b42 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/TermXmlBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/TermXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class TermXmlBasicAuthTest extends TermResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyJsonBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyJsonBasicAuthTest.php
index ec0d67e2b2..bab8243704 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyJsonBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class VocabularyJsonBasicAuthTest extends VocabularyResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyResourceTestBase.php b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyResourceTestBase.php
index b1e87d986e..90781ae5eb 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyResourceTestBase.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyXmlBasicAuthTest.php b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyXmlBasicAuthTest.php
index 52b3741a9a..25b4bad952 100644
--- a/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyXmlBasicAuthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Rest/VocabularyXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class VocabularyXmlBasicAuthTest extends VocabularyResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/TaxonomyImageTest.php b/core/modules/taxonomy/tests/src/Functional/TaxonomyImageTest.php
index fc2fe62432..8d83097a6c 100644
--- a/core/modules/taxonomy/tests/src/Functional/TaxonomyImageTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TaxonomyImageTest.php
@@ -32,7 +32,7 @@ class TaxonomyImageTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/TaxonomyQueryAlterTest.php b/core/modules/taxonomy/tests/src/Functional/TaxonomyQueryAlterTest.php
index 81bd6796b5..b18ad9ff69 100644
--- a/core/modules/taxonomy/tests/src/Functional/TaxonomyQueryAlterTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TaxonomyQueryAlterTest.php
@@ -18,7 +18,7 @@ class TaxonomyQueryAlterTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'taxonomy_test'];
+  protected static $modules = ['taxonomy', 'taxonomy_test'];
 
   /**
    * Tests that appropriate tags are added when querying the database.
diff --git a/core/modules/taxonomy/tests/src/Functional/TaxonomyTermPagerTest.php b/core/modules/taxonomy/tests/src/Functional/TaxonomyTermPagerTest.php
index 66782f3e7a..0a72651fa7 100644
--- a/core/modules/taxonomy/tests/src/Functional/TaxonomyTermPagerTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TaxonomyTermPagerTest.php
@@ -14,7 +14,7 @@ class TaxonomyTermPagerTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Vocabulary for testing.
diff --git a/core/modules/taxonomy/tests/src/Functional/TaxonomyTestBase.php b/core/modules/taxonomy/tests/src/Functional/TaxonomyTestBase.php
index fdbfccd303..51df0af52f 100644
--- a/core/modules/taxonomy/tests/src/Functional/TaxonomyTestBase.php
+++ b/core/modules/taxonomy/tests/src/Functional/TaxonomyTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'block'];
+  protected static $modules = ['taxonomy', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/TermCacheTagsTest.php b/core/modules/taxonomy/tests/src/Functional/TermCacheTagsTest.php
index 378d02c755..7b52311ed2 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermCacheTagsTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermCacheTagsTest.php
@@ -16,7 +16,7 @@ class TermCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
index 997e698b9e..0581b090a9 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermContextualLinksTest.php
@@ -12,7 +12,7 @@ class TermContextualLinksTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
   ];
 
diff --git a/core/modules/taxonomy/tests/src/Functional/TermEntityReferenceTest.php b/core/modules/taxonomy/tests/src/Functional/TermEntityReferenceTest.php
index 9d4522ec71..350982271e 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermEntityReferenceTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermEntityReferenceTest.php
@@ -17,7 +17,7 @@ class TermEntityReferenceTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_reference_test', 'entity_test'];
+  protected static $modules = ['entity_reference_test', 'entity_test'];
 
   /**
    * Tests an entity reference field restricted to a single vocabulary.
diff --git a/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php b/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php
index 83ab04d5e1..5aca546d09 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php
@@ -16,7 +16,7 @@ class TermIndexTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * Vocabulary for testing.
diff --git a/core/modules/taxonomy/tests/src/Functional/TermLanguageTest.php b/core/modules/taxonomy/tests/src/Functional/TermLanguageTest.php
index f60e77e534..8de70dcaa9 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermLanguageTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermLanguageTest.php
@@ -12,7 +12,7 @@
  */
 class TermLanguageTest extends TaxonomyTestBase {
 
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Vocabulary for testing.
diff --git a/core/modules/taxonomy/tests/src/Functional/TermTranslationFieldViewTest.php b/core/modules/taxonomy/tests/src/Functional/TermTranslationFieldViewTest.php
index 236ac70553..bb18e3159c 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermTranslationFieldViewTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermTranslationFieldViewTest.php
@@ -39,7 +39,7 @@ class TermTranslationFieldViewTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'taxonomy'];
+  protected static $modules = ['language', 'content_translation', 'taxonomy'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/TermTranslationUITest.php b/core/modules/taxonomy/tests/src/Functional/TermTranslationUITest.php
index 0d24b6990e..f0681734c7 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermTranslationUITest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermTranslationUITest.php
@@ -25,7 +25,7 @@ class TermTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'taxonomy'];
+  protected static $modules = ['language', 'content_translation', 'taxonomy'];
 
   protected function setUp() {
     $this->entityTypeId = 'taxonomy_term';
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/ArgumentValidatorTermTest.php b/core/modules/taxonomy/tests/src/Functional/Views/ArgumentValidatorTermTest.php
index 8260565e36..16d1a2b923 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/ArgumentValidatorTermTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/ArgumentValidatorTermTest.php
@@ -38,7 +38,7 @@ class ArgumentValidatorTermTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'views_test_config'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'views_test_config'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyFieldFilterTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyFieldFilterTest.php
index 1b8bbcaa51..c68817801a 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyFieldFilterTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyFieldFilterTest.php
@@ -22,7 +22,7 @@ class TaxonomyFieldFilterTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'taxonomy', 'taxonomy_test_views', 'text', 'views', 'node'];
+  protected static $modules = ['language', 'taxonomy', 'taxonomy_test_views', 'text', 'views', 'node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidFilterTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidFilterTest.php
index 6fd1eba865..b459304dae 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidFilterTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidFilterTest.php
@@ -19,7 +19,7 @@ class TaxonomyIndexTidFilterTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php
index 992e5bee18..c7874b5b27 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php
@@ -31,7 +31,7 @@ class TaxonomyIndexTidUiTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'taxonomy', 'views', 'views_ui', 'taxonomy_test_views'];
+  protected static $modules = ['node', 'taxonomy', 'views', 'views_ui', 'taxonomy_test_views'];
 
   /**
    * A nested array of \Drupal\taxonomy\TermInterface objects.
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyParentUITest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyParentUITest.php
index d8ab8ea121..40985e7ceb 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyParentUITest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyParentUITest.php
@@ -25,7 +25,7 @@ class TaxonomyParentUITest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermArgumentDepthTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermArgumentDepthTest.php
index 3505784a07..c37b9a527d 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermArgumentDepthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermArgumentDepthTest.php
@@ -12,7 +12,7 @@ class TaxonomyTermArgumentDepthTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermFilterDepthTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermFilterDepthTest.php
index 4d7a4fdf03..3b065314b7 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermFilterDepthTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermFilterDepthTest.php
@@ -14,7 +14,7 @@ class TaxonomyTermFilterDepthTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'views', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php
index fc0cddce48..e3df7ad6c8 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php
@@ -21,7 +21,7 @@ class TaxonomyTermViewTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'views'];
+  protected static $modules = ['taxonomy', 'views'];
 
   /**
    * An user with permissions to administer taxonomy.
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTestBase.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTestBase.php
index a2d8ec14a3..0eb4cbf46b 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTestBase.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTestBase.php
@@ -22,7 +22,7 @@
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views'];
 
   /**
    * Stores the nodes used for the different tests.
diff --git a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyVocabularyArgumentTest.php b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyVocabularyArgumentTest.php
index 8b1d58cf29..721df17d7b 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyVocabularyArgumentTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyVocabularyArgumentTest.php
@@ -14,7 +14,7 @@ class TaxonomyVocabularyArgumentTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'views'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php b/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php
index 1fb01630bf..0243e209fc 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php
@@ -18,7 +18,7 @@ class VocabularyCrudTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test', 'taxonomy_crud'];
+  protected static $modules = ['field_test', 'taxonomy_crud'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php b/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php
index c94d64e287..fd607aba71 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php
@@ -12,7 +12,7 @@
  */
 class VocabularyLanguageTest extends TaxonomyTestBase {
 
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/VocabularyPermissionsTest.php b/core/modules/taxonomy/tests/src/Functional/VocabularyPermissionsTest.php
index bb94a96da6..8690cfbe1e 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyPermissionsTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyPermissionsTest.php
@@ -16,7 +16,7 @@ class VocabularyPermissionsTest extends TaxonomyTestBase {
    *
    * @var array
    */
-  public static $modules = ['help'];
+  protected static $modules = ['help'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/taxonomy/tests/src/Functional/VocabularySerializationTest.php b/core/modules/taxonomy/tests/src/Functional/VocabularySerializationTest.php
index b9aba8a798..16621b3390 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularySerializationTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularySerializationTest.php
@@ -21,7 +21,7 @@ class VocabularySerializationTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'vocabulary_serialization_test'];
+  protected static $modules = ['taxonomy', 'vocabulary_serialization_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php b/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php
index aa98ac3330..6807297238 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php
@@ -12,7 +12,7 @@ class VocabularyTranslationTest extends TaxonomyTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['content_translation', 'language'];
+  protected static $modules = ['content_translation', 'language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyConfigsTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyConfigsTest.php
index 92ebe5926a..e0480170b1 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyConfigsTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateTaxonomyConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyTermStubTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyTermStubTest.php
index 2da51e4a43..1d340fc155 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyTermStubTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/MigrateTaxonomyTermStubTest.php
@@ -20,7 +20,7 @@ class MigrateTaxonomyTermStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'text', 'taxonomy_term_stub_test'];
+  protected static $modules = ['taxonomy', 'text', 'taxonomy_term_stub_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTest.php
index 75c79241e0..c14f39859c 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTest.php
@@ -15,7 +15,7 @@ class MigrateTaxonomyTermTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTest.php
index 1584c5cc73..cf2a353536 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTest.php
@@ -15,7 +15,7 @@ class MigrateTaxonomyVocabularyTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTranslationTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTranslationTest.php
index 9d7176c497..176344b36f 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyVocabularyTranslationTest.php
@@ -14,7 +14,7 @@ class MigrateTaxonomyVocabularyTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'language',
     'taxonomy',
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeRevisionTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeRevisionTest.php
index 25544486ab..4f98ed3b65 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeRevisionTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeRevisionTest.php
@@ -14,7 +14,7 @@ class MigrateTermNodeRevisionTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'menu_ui'];
+  protected static $modules = ['taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeTest.php
index 8e7d13de0e..eb8e0922bb 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTermNodeTest.php
@@ -15,7 +15,7 @@ class MigrateTermNodeTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'menu_ui'];
+  protected static $modules = ['taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityDisplayTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityDisplayTest.php
index 6b6ee945c6..74de1b630d 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityDisplayTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateVocabularyEntityDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'taxonomy', 'menu_ui'];
+  protected static $modules = ['field', 'taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityFormDisplayTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityFormDisplayTest.php
index 7cfc306a98..1e332ca821 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityFormDisplayTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyEntityFormDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateVocabularyEntityFormDisplayTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'menu_ui'];
+  protected static $modules = ['taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldInstanceTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldInstanceTest.php
index 77cb3e9069..fdbdb46c9f 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldInstanceTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldInstanceTest.php
@@ -15,7 +15,7 @@ class MigrateVocabularyFieldInstanceTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'menu_ui'];
+  protected static $modules = ['taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldTest.php
index fa5c7f3a16..9cdb0c323b 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateVocabularyFieldTest.php
@@ -15,7 +15,7 @@ class MigrateVocabularyFieldTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'menu_ui'];
+  protected static $modules = ['taxonomy', 'menu_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateNodeTaxonomyTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateNodeTaxonomyTest.php
index e8c6fefa8b..c7b5738149 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateNodeTaxonomyTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateNodeTaxonomyTest.php
@@ -14,7 +14,7 @@
  */
 class MigrateNodeTaxonomyTest extends MigrateDrupal7TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'datetime',
     'field',
     'filter',
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyTermTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyTermTest.php
index e4246594a9..269a8a12d9 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyTermTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyTermTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateTaxonomyTermTest extends MigrateDrupal7TestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'datetime',
     'forum',
diff --git a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyVocabularyTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyVocabularyTest.php
index 5663ea6cda..10220bd34d 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyVocabularyTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d7/MigrateTaxonomyVocabularyTest.php
@@ -16,7 +16,7 @@ class MigrateTaxonomyVocabularyTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/PendingRevisionTest.php b/core/modules/taxonomy/tests/src/Kernel/PendingRevisionTest.php
index e4b2cc051c..ed9acf609b 100644
--- a/core/modules/taxonomy/tests/src/Kernel/PendingRevisionTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/PendingRevisionTest.php
@@ -20,7 +20,7 @@ class PendingRevisionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'node', 'user', 'text', 'field', 'system'];
+  protected static $modules = ['taxonomy', 'node', 'user', 'text', 'field', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermNodeTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermNodeTest.php
index 3084acffae..16a365a2af 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermNodeTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermNodeTest.php
@@ -15,7 +15,7 @@ class TermNodeTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermSourceWithVocabularyFilterTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermSourceWithVocabularyFilterTest.php
index 42fa75d0ff..bb60f9c4b9 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermSourceWithVocabularyFilterTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermSourceWithVocabularyFilterTest.php
@@ -13,7 +13,7 @@ class TermSourceWithVocabularyFilterTest extends TermTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTest.php
index d1ac238ae2..c0b50cb0f6 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTest.php
@@ -15,7 +15,7 @@ class TermTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTranslationTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTranslationTest.php
index af69e30e37..cafbc813b9 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/TermTranslationTest.php
@@ -15,7 +15,7 @@ class TermTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTest.php
index a98b2985ed..4b81b6c3fb 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTest.php
@@ -16,7 +16,7 @@ class VocabularyTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTranslationTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTranslationTest.php
index e54eb6ee3f..1c5522c5fe 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d6/VocabularyTranslationTest.php
@@ -15,7 +15,7 @@ class VocabularyTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermSourceWithVocabularyFilterTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermSourceWithVocabularyFilterTest.php
index 671bb554ed..274d586d74 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermSourceWithVocabularyFilterTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermSourceWithVocabularyFilterTest.php
@@ -13,7 +13,7 @@ class TermSourceWithVocabularyFilterTest extends TermTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermTest.php
index ef002cfec8..ab2cb58d51 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/TermTest.php
@@ -15,7 +15,7 @@ class TermTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTest.php b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTest.php
index 4d1975ceb4..fb78c547d7 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Plugin/migrate/source/d7/VocabularyTest.php
@@ -15,7 +15,7 @@ class VocabularyTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'migrate_drupal'];
+  protected static $modules = ['taxonomy', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
index 3d8bff80a3..a9b1f5df20 100644
--- a/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
@@ -18,7 +18,7 @@ class TermKernelTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['filter', 'taxonomy', 'text', 'user'];
+  protected static $modules = ['filter', 'taxonomy', 'text', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php b/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
index 437a305f6f..97784673dd 100644
--- a/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
@@ -16,7 +16,7 @@ class TermValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyFieldVidTest.php b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyFieldVidTest.php
index 2fde283e32..2bd6005d20 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyFieldVidTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyFieldVidTest.php
@@ -24,7 +24,7 @@ class TaxonomyFieldVidTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'taxonomy_test_views', 'text', 'filter'];
+  protected static $modules = ['taxonomy', 'taxonomy_test_views', 'text', 'filter'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyTestBase.php b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyTestBase.php
index a9f4c474be..a1a310b7aa 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyTestBase.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyTestBase.php
@@ -32,7 +32,7 @@
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'taxonomy',
     'taxonomy_test_views',
     'text',
diff --git a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyViewsFieldAccessTest.php b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyViewsFieldAccessTest.php
index e62232befd..2d7b960e39 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyViewsFieldAccessTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyViewsFieldAccessTest.php
@@ -16,7 +16,7 @@ class TaxonomyViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'text', 'entity_test'];
+  protected static $modules = ['taxonomy', 'text', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/telephone/tests/src/Functional/TelephoneFieldTest.php b/core/modules/telephone/tests/src/Functional/TelephoneFieldTest.php
index 75e626f66d..b1f52471d7 100644
--- a/core/modules/telephone/tests/src/Functional/TelephoneFieldTest.php
+++ b/core/modules/telephone/tests/src/Functional/TelephoneFieldTest.php
@@ -18,7 +18,7 @@ class TelephoneFieldTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'field',
     'node',
     'telephone',
diff --git a/core/modules/telephone/tests/src/Kernel/TelephoneItemTest.php b/core/modules/telephone/tests/src/Kernel/TelephoneItemTest.php
index 72269409e4..11b65120da 100644
--- a/core/modules/telephone/tests/src/Kernel/TelephoneItemTest.php
+++ b/core/modules/telephone/tests/src/Kernel/TelephoneItemTest.php
@@ -21,7 +21,7 @@ class TelephoneItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['telephone'];
+  protected static $modules = ['telephone'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
index 88153abce5..5ce2083b54 100644
--- a/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
+++ b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
@@ -15,7 +15,7 @@ class TextareaWithSummaryTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['text', 'node'];
+  protected static $modules = ['text', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/text/tests/src/Kernel/TextFormatterTest.php b/core/modules/text/tests/src/Kernel/TextFormatterTest.php
index c75ac34bc4..d75bcc40c6 100644
--- a/core/modules/text/tests/src/Kernel/TextFormatterTest.php
+++ b/core/modules/text/tests/src/Kernel/TextFormatterTest.php
@@ -33,7 +33,7 @@ class TextFormatterTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['text'];
+  protected static $modules = ['text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/text/tests/src/Kernel/TextSummaryTest.php b/core/modules/text/tests/src/Kernel/TextSummaryTest.php
index 2eeaf2de0b..25641b4197 100644
--- a/core/modules/text/tests/src/Kernel/TextSummaryTest.php
+++ b/core/modules/text/tests/src/Kernel/TextSummaryTest.php
@@ -12,7 +12,7 @@
  */
 class TextSummaryTest extends KernelTestBase {
 
-  public static $modules = ['system', 'user', 'filter', 'text'];
+  protected static $modules = ['system', 'user', 'filter', 'text'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
index 195250abb9..70c2af1a99 100644
--- a/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
+++ b/core/modules/text/tests/src/Kernel/TextWithSummaryItemTest.php
@@ -21,7 +21,7 @@ class TextWithSummaryItemTest extends FieldKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter'];
+  protected static $modules = ['filter'];
 
   /**
    * Field storage entity.
diff --git a/core/modules/toolbar/tests/src/Functional/ToolbarAdminMenuTest.php b/core/modules/toolbar/tests/src/Functional/ToolbarAdminMenuTest.php
index 9585c86eb4..400cb974ba 100644
--- a/core/modules/toolbar/tests/src/Functional/ToolbarAdminMenuTest.php
+++ b/core/modules/toolbar/tests/src/Functional/ToolbarAdminMenuTest.php
@@ -54,7 +54,7 @@ class ToolbarAdminMenuTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'menu_ui', 'user', 'taxonomy', 'toolbar', 'language', 'test_page_test', 'locale'];
+  protected static $modules = ['node', 'block', 'menu_ui', 'user', 'taxonomy', 'toolbar', 'language', 'test_page_test', 'locale'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/toolbar/tests/src/Functional/ToolbarCacheContextsTest.php b/core/modules/toolbar/tests/src/Functional/ToolbarCacheContextsTest.php
index 0232545473..c114978d7b 100644
--- a/core/modules/toolbar/tests/src/Functional/ToolbarCacheContextsTest.php
+++ b/core/modules/toolbar/tests/src/Functional/ToolbarCacheContextsTest.php
@@ -21,7 +21,7 @@ class ToolbarCacheContextsTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['toolbar', 'test_page_test'];
+  protected static $modules = ['toolbar', 'test_page_test'];
 
   /**
    * An authenticated user to use for testing.
diff --git a/core/modules/toolbar/tests/src/Functional/ToolbarHookToolbarTest.php b/core/modules/toolbar/tests/src/Functional/ToolbarHookToolbarTest.php
index f3d3ce6118..19ebfc62e3 100644
--- a/core/modules/toolbar/tests/src/Functional/ToolbarHookToolbarTest.php
+++ b/core/modules/toolbar/tests/src/Functional/ToolbarHookToolbarTest.php
@@ -23,7 +23,7 @@ class ToolbarHookToolbarTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['toolbar', 'toolbar_test', 'test_page_test'];
+  protected static $modules = ['toolbar', 'toolbar_test', 'test_page_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/toolbar/tests/src/Functional/ToolbarMenuTranslationTest.php b/core/modules/toolbar/tests/src/Functional/ToolbarMenuTranslationTest.php
index 995d49ee38..a954a85c3f 100644
--- a/core/modules/toolbar/tests/src/Functional/ToolbarMenuTranslationTest.php
+++ b/core/modules/toolbar/tests/src/Functional/ToolbarMenuTranslationTest.php
@@ -23,7 +23,7 @@ class ToolbarMenuTranslationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['toolbar', 'toolbar_test', 'locale', 'locale_test'];
+  protected static $modules = ['toolbar', 'toolbar_test', 'locale', 'locale_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/toolbar/tests/src/FunctionalJavascript/ToolbarIntegrationTest.php b/core/modules/toolbar/tests/src/FunctionalJavascript/ToolbarIntegrationTest.php
index fd163985e7..1ed7b6cb11 100644
--- a/core/modules/toolbar/tests/src/FunctionalJavascript/ToolbarIntegrationTest.php
+++ b/core/modules/toolbar/tests/src/FunctionalJavascript/ToolbarIntegrationTest.php
@@ -14,7 +14,7 @@ class ToolbarIntegrationTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['toolbar', 'node'];
+  protected static $modules = ['toolbar', 'node'];
 
   /**
    * Tests if the toolbar can be toggled with JavaScript.
diff --git a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonAnonTest.php b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonAnonTest.php
index 1461fc1a88..cf112a2fa8 100644
--- a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonAnonTest.php
+++ b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class TourHalJsonAnonTest extends TourResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonBasicAuthTest.php b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonBasicAuthTest.php
index c79f55e48e..8d65c30e3f 100644
--- a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonBasicAuthTest.php
+++ b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class TourHalJsonBasicAuthTest extends TourResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonCookieTest.php b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonCookieTest.php
index 6a7737db08..e808503f2f 100644
--- a/core/modules/tour/tests/src/Functional/Hal/TourHalJsonCookieTest.php
+++ b/core/modules/tour/tests/src/Functional/Hal/TourHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class TourHalJsonCookieTest extends TourResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/Rest/TourJsonBasicAuthTest.php b/core/modules/tour/tests/src/Functional/Rest/TourJsonBasicAuthTest.php
index fb1ff6995c..3a1215e5c1 100644
--- a/core/modules/tour/tests/src/Functional/Rest/TourJsonBasicAuthTest.php
+++ b/core/modules/tour/tests/src/Functional/Rest/TourJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class TourJsonBasicAuthTest extends TourResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/Rest/TourResourceTestBase.php b/core/modules/tour/tests/src/Functional/Rest/TourResourceTestBase.php
index a0f35f5316..157dbd4ad6 100644
--- a/core/modules/tour/tests/src/Functional/Rest/TourResourceTestBase.php
+++ b/core/modules/tour/tests/src/Functional/Rest/TourResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['tour'];
+  protected static $modules = ['tour'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/Rest/TourXmlBasicAuthTest.php b/core/modules/tour/tests/src/Functional/Rest/TourXmlBasicAuthTest.php
index 618b41defd..617530e69c 100644
--- a/core/modules/tour/tests/src/Functional/Rest/TourXmlBasicAuthTest.php
+++ b/core/modules/tour/tests/src/Functional/Rest/TourXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class TourXmlBasicAuthTest extends TourResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/TourCacheTagsTest.php b/core/modules/tour/tests/src/Functional/TourCacheTagsTest.php
index daed6fa292..32621bc50c 100644
--- a/core/modules/tour/tests/src/Functional/TourCacheTagsTest.php
+++ b/core/modules/tour/tests/src/Functional/TourCacheTagsTest.php
@@ -18,7 +18,7 @@ class TourCacheTagsTest extends PageCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['tour', 'tour_test'];
+  protected static $modules = ['tour', 'tour_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tour/tests/src/Functional/TourHelpPageTest.php b/core/modules/tour/tests/src/Functional/TourHelpPageTest.php
index ad60df104f..de8fb3023e 100644
--- a/core/modules/tour/tests/src/Functional/TourHelpPageTest.php
+++ b/core/modules/tour/tests/src/Functional/TourHelpPageTest.php
@@ -16,7 +16,7 @@ class TourHelpPageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['help', 'tour', 'locale', 'language'];
+  protected static $modules = ['help', 'tour', 'locale', 'language'];
 
   /**
    * User that can access tours and help.
diff --git a/core/modules/tour/tests/src/Functional/TourTest.php b/core/modules/tour/tests/src/Functional/TourTest.php
index 1db1bb8cae..b4101dda5d 100644
--- a/core/modules/tour/tests/src/Functional/TourTest.php
+++ b/core/modules/tour/tests/src/Functional/TourTest.php
@@ -17,7 +17,7 @@ class TourTest extends TourTestBasic {
    *
    * @var array
    */
-  public static $modules = ['block', 'tour', 'locale', 'language', 'tour_test'];
+  protected static $modules = ['block', 'tour', 'locale', 'language', 'tour_test'];
 
   /**
    * The permissions required for a logged in user to test tour tips.
diff --git a/core/modules/tour/tests/src/Kernel/TourPluginTest.php b/core/modules/tour/tests/src/Kernel/TourPluginTest.php
index ce47467df7..732f9127ea 100644
--- a/core/modules/tour/tests/src/Kernel/TourPluginTest.php
+++ b/core/modules/tour/tests/src/Kernel/TourPluginTest.php
@@ -16,7 +16,7 @@ class TourPluginTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['tour'];
+  protected static $modules = ['tour'];
 
   /**
    * Stores the tour plugin manager.
diff --git a/core/modules/tracker/src/Tests/Views/TrackerTestBase.php b/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
index 4dfaab03bc..7c7e8f6e4d 100644
--- a/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
+++ b/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
@@ -25,7 +25,7 @@
    *
    * @var array
    */
-  public static $modules = ['comment', 'tracker', 'tracker_test_views'];
+  protected static $modules = ['comment', 'tracker', 'tracker_test_views'];
 
   /**
    * The node used for testing.
diff --git a/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php b/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php
index 2b320ae4b6..8fa2b89fd8 100644
--- a/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php
+++ b/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php
@@ -21,7 +21,7 @@ class TrackerNodeAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'tracker', 'node_access_test'];
+  protected static $modules = ['node', 'comment', 'tracker', 'node_access_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/tracker/tests/src/Functional/TrackerTest.php b/core/modules/tracker/tests/src/Functional/TrackerTest.php
index 75b7b5cde7..957b206c70 100644
--- a/core/modules/tracker/tests/src/Functional/TrackerTest.php
+++ b/core/modules/tracker/tests/src/Functional/TrackerTest.php
@@ -27,7 +27,7 @@ class TrackerTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'comment', 'tracker', 'history', 'node_test'];
+  protected static $modules = ['block', 'comment', 'tracker', 'history', 'node_test'];
 
   /**
    * The main user for testing.
diff --git a/core/modules/tracker/tests/src/Functional/Views/TrackerTestBase.php b/core/modules/tracker/tests/src/Functional/Views/TrackerTestBase.php
index d70684378c..0c7ebdd75c 100644
--- a/core/modules/tracker/tests/src/Functional/Views/TrackerTestBase.php
+++ b/core/modules/tracker/tests/src/Functional/Views/TrackerTestBase.php
@@ -20,7 +20,7 @@
    *
    * @var array
    */
-  public static $modules = ['comment', 'tracker', 'tracker_test_views'];
+  protected static $modules = ['comment', 'tracker', 'tracker_test_views'];
 
   /**
    * The node used for testing.
diff --git a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerNodeTest.php b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerNodeTest.php
index d37050269f..fa0674f431 100644
--- a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerNodeTest.php
+++ b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerNodeTest.php
@@ -15,7 +15,7 @@ class MigrateTrackerNodeTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_ui',
     'node',
     'text',
diff --git a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerSettingsTest.php b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerSettingsTest.php
index ea9732221a..552774b298 100644
--- a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerSettingsTest.php
+++ b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerSettingsTest.php
@@ -11,7 +11,7 @@
  */
 class MigrateTrackerSettingsTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['tracker'];
+  protected static $modules = ['tracker'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerUserTest.php b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerUserTest.php
index 3b0c11bb32..2282070668 100644
--- a/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerUserTest.php
+++ b/core/modules/tracker/tests/src/Kernel/Migrate/d7/MigrateTrackerUserTest.php
@@ -15,7 +15,7 @@ class MigrateTrackerUserTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_ui',
     'node',
     'text',
diff --git a/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerNodeTest.php b/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerNodeTest.php
index 28d3772614..9f1c0978a0 100644
--- a/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerNodeTest.php
+++ b/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerNodeTest.php
@@ -16,7 +16,7 @@ class TrackerNodeTest extends MigrateSqlSourceTestBase {
   /**
   * {@inheritdoc}
   */
-  public static $modules = ['tracker', 'migrate_drupal'];
+  protected static $modules = ['tracker', 'migrate_drupal'];
 
   /**
   * {@inheritdoc}
diff --git a/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerUserTest.php b/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerUserTest.php
index 293e559a20..d609d0d1e3 100644
--- a/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerUserTest.php
+++ b/core/modules/tracker/tests/src/Kernel/Plugin/migrate/source/d7/TrackerUserTest.php
@@ -16,7 +16,7 @@ class TrackerUserTest extends MigrateSqlSourceTestBase {
   /**
   * {@inheritdoc}
   */
-  public static $modules = ['tracker', 'migrate_drupal'];
+  protected static $modules = ['tracker', 'migrate_drupal'];
 
   /**
   * {@inheritdoc}
diff --git a/core/modules/update/tests/src/Functional/FileTransferAuthorizeFormTest.php b/core/modules/update/tests/src/Functional/FileTransferAuthorizeFormTest.php
index d768b06d81..cac85123ac 100644
--- a/core/modules/update/tests/src/Functional/FileTransferAuthorizeFormTest.php
+++ b/core/modules/update/tests/src/Functional/FileTransferAuthorizeFormTest.php
@@ -14,7 +14,7 @@ class FileTransferAuthorizeFormTest extends UpdateTestBase {
    *
    * @var array
    */
-  public static $modules = ['update', 'update_test'];
+  protected static $modules = ['update', 'update_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/update/tests/src/Functional/UpdateContribTest.php b/core/modules/update/tests/src/Functional/UpdateContribTest.php
index c2325376da..fa97c7a9b3 100644
--- a/core/modules/update/tests/src/Functional/UpdateContribTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateContribTest.php
@@ -18,7 +18,7 @@ class UpdateContribTest extends UpdateTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test', 'update', 'aaa_update_test', 'bbb_update_test', 'ccc_update_test'];
+  protected static $modules = ['update_test', 'update', 'aaa_update_test', 'bbb_update_test', 'ccc_update_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/update/tests/src/Functional/UpdateCoreTest.php b/core/modules/update/tests/src/Functional/UpdateCoreTest.php
index dc7da67380..23c6ccb56a 100644
--- a/core/modules/update/tests/src/Functional/UpdateCoreTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateCoreTest.php
@@ -20,7 +20,7 @@ class UpdateCoreTest extends UpdateTestBase {
    *
    * @var array
    */
-  public static $modules = ['update_test', 'update', 'language', 'block'];
+  protected static $modules = ['update_test', 'update', 'language', 'block'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/update/tests/src/Functional/UpdateDeleteFileIfStaleTest.php b/core/modules/update/tests/src/Functional/UpdateDeleteFileIfStaleTest.php
index 33c4ed3f0f..c1487d6938 100644
--- a/core/modules/update/tests/src/Functional/UpdateDeleteFileIfStaleTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateDeleteFileIfStaleTest.php
@@ -14,7 +14,7 @@ class UpdateDeleteFileIfStaleTest extends UpdateTestBase {
    *
    * @var array
    */
-  public static $modules = ['update'];
+  protected static $modules = ['update'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/update/tests/src/Functional/UpdateUploadTest.php b/core/modules/update/tests/src/Functional/UpdateUploadTest.php
index e86dff5498..9a03e7a335 100644
--- a/core/modules/update/tests/src/Functional/UpdateUploadTest.php
+++ b/core/modules/update/tests/src/Functional/UpdateUploadTest.php
@@ -23,7 +23,7 @@ class UpdateUploadTest extends UpdateTestBase {
    *
    * @var array
    */
-  public static $modules = ['update', 'update_test'];
+  protected static $modules = ['update', 'update_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/update/tests/src/Kernel/Migrate/d6/MigrateUpdateConfigsTest.php b/core/modules/update/tests/src/Kernel/Migrate/d6/MigrateUpdateConfigsTest.php
index aa3563c608..a7d2349f2a 100644
--- a/core/modules/update/tests/src/Kernel/Migrate/d6/MigrateUpdateConfigsTest.php
+++ b/core/modules/update/tests/src/Kernel/Migrate/d6/MigrateUpdateConfigsTest.php
@@ -17,7 +17,7 @@ class MigrateUpdateConfigsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['update'];
+  protected static $modules = ['update'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/Functional/UserPasswordResetTest.php b/core/modules/user/src/Tests/Functional/UserPasswordResetTest.php
index 11d0691350..b56bc1b604 100644
--- a/core/modules/user/src/Tests/Functional/UserPasswordResetTest.php
+++ b/core/modules/user/src/Tests/Functional/UserPasswordResetTest.php
@@ -31,7 +31,7 @@ class UserPasswordResetTest extends PageCacheTagsTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/FunctionalJavascript/UserPasswordResetTest.php b/core/modules/user/src/Tests/FunctionalJavascript/UserPasswordResetTest.php
index caad739175..d30f2d81c7 100644
--- a/core/modules/user/src/Tests/FunctionalJavascript/UserPasswordResetTest.php
+++ b/core/modules/user/src/Tests/FunctionalJavascript/UserPasswordResetTest.php
@@ -44,7 +44,7 @@ class UserPasswordResetTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/RestRegisterUserTest.php b/core/modules/user/src/Tests/RestRegisterUserTest.php
index 31bcce4d29..6b574083f0 100644
--- a/core/modules/user/src/Tests/RestRegisterUserTest.php
+++ b/core/modules/user/src/Tests/RestRegisterUserTest.php
@@ -17,7 +17,7 @@ class RestRegisterUserTest extends RESTTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/UserAdminLanguageTest.php b/core/modules/user/src/Tests/UserAdminLanguageTest.php
index cd6cc657bf..be5453d1b6 100644
--- a/core/modules/user/src/Tests/UserAdminLanguageTest.php
+++ b/core/modules/user/src/Tests/UserAdminLanguageTest.php
@@ -31,7 +31,7 @@ class UserAdminLanguageTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'language', 'language_test'];
+  protected static $modules = ['user', 'language', 'language_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/user/src/Tests/UserAdminSettingsFormTest.php b/core/modules/user/src/Tests/UserAdminSettingsFormTest.php
index 784d5e1e62..375f41a588 100644
--- a/core/modules/user/src/Tests/UserAdminSettingsFormTest.php
+++ b/core/modules/user/src/Tests/UserAdminSettingsFormTest.php
@@ -15,7 +15,7 @@ class UserAdminSettingsFormTest extends ConfigFormTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/UserBlocksTest.php b/core/modules/user/src/Tests/UserBlocksTest.php
index b7e6cad7e3..09b641b407 100644
--- a/core/modules/user/src/Tests/UserBlocksTest.php
+++ b/core/modules/user/src/Tests/UserBlocksTest.php
@@ -17,7 +17,7 @@ class UserBlocksTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'views'];
+  protected static $modules = ['block', 'views'];
 
   /**
    * A user with the 'administer blocks' permission.
diff --git a/core/modules/user/src/Tests/UserCreateTest.php b/core/modules/user/src/Tests/UserCreateTest.php
index 7b534435a0..049019e206 100644
--- a/core/modules/user/src/Tests/UserCreateTest.php
+++ b/core/modules/user/src/Tests/UserCreateTest.php
@@ -18,7 +18,7 @@ class UserCreateTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * Create a user through the administration interface and ensure that it
diff --git a/core/modules/user/src/Tests/UserRegistrationTest.php b/core/modules/user/src/Tests/UserRegistrationTest.php
index 95fd7a0999..fc73d53a20 100644
--- a/core/modules/user/src/Tests/UserRegistrationTest.php
+++ b/core/modules/user/src/Tests/UserRegistrationTest.php
@@ -21,7 +21,7 @@ class UserRegistrationTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   public function testRegistrationWithEmailVerification() {
     $config = $this->config('user.settings');
diff --git a/core/modules/user/tests/src/Functional/AccessRoleUITest.php b/core/modules/user/tests/src/Functional/AccessRoleUITest.php
index 6c1004c9d4..e33d9b532a 100644
--- a/core/modules/user/tests/src/Functional/AccessRoleUITest.php
+++ b/core/modules/user/tests/src/Functional/AccessRoleUITest.php
@@ -25,7 +25,7 @@ class AccessRoleUITest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'user_test_views'];
+  protected static $modules = ['user', 'user_test_views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonAnonTest.php b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonAnonTest.php
index a08a1d094a..697417bb45 100644
--- a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonAnonTest.php
+++ b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class RoleHalJsonAnonTest extends RoleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonBasicAuthTest.php b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonBasicAuthTest.php
index 1e613e5d73..f5c1e8c73e 100644
--- a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class RoleHalJsonBasicAuthTest extends RoleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonCookieTest.php b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonCookieTest.php
index 0074e0516c..9b2c833d50 100644
--- a/core/modules/user/tests/src/Functional/Hal/RoleHalJsonCookieTest.php
+++ b/core/modules/user/tests/src/Functional/Hal/RoleHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class RoleHalJsonCookieTest extends RoleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Hal/UserHalJsonAnonTest.php b/core/modules/user/tests/src/Functional/Hal/UserHalJsonAnonTest.php
index b33c6868bc..48be944ebd 100644
--- a/core/modules/user/tests/src/Functional/Hal/UserHalJsonAnonTest.php
+++ b/core/modules/user/tests/src/Functional/Hal/UserHalJsonAnonTest.php
@@ -17,7 +17,7 @@ class UserHalJsonAnonTest extends UserResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Hal/UserHalJsonBasicAuthTest.php b/core/modules/user/tests/src/Functional/Hal/UserHalJsonBasicAuthTest.php
index 7da859e060..97e3038f58 100644
--- a/core/modules/user/tests/src/Functional/Hal/UserHalJsonBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Hal/UserHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class UserHalJsonBasicAuthTest extends UserHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/RoleJsonBasicAuthTest.php b/core/modules/user/tests/src/Functional/Rest/RoleJsonBasicAuthTest.php
index 79d16cb90b..c0d572855a 100644
--- a/core/modules/user/tests/src/Functional/Rest/RoleJsonBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Rest/RoleJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class RoleJsonBasicAuthTest extends RoleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/RoleResourceTestBase.php b/core/modules/user/tests/src/Functional/Rest/RoleResourceTestBase.php
index 18ff4842a9..1bb24b676e 100644
--- a/core/modules/user/tests/src/Functional/Rest/RoleResourceTestBase.php
+++ b/core/modules/user/tests/src/Functional/Rest/RoleResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/RoleXmlBasicAuthTest.php b/core/modules/user/tests/src/Functional/Rest/RoleXmlBasicAuthTest.php
index fa98edd47c..bc661a49c8 100644
--- a/core/modules/user/tests/src/Functional/Rest/RoleXmlBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Rest/RoleXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class RoleXmlBasicAuthTest extends RoleResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/UserJsonBasicAuthTest.php b/core/modules/user/tests/src/Functional/Rest/UserJsonBasicAuthTest.php
index 7a1ea2674e..80aa29722d 100644
--- a/core/modules/user/tests/src/Functional/Rest/UserJsonBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Rest/UserJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class UserJsonBasicAuthTest extends UserResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/UserResourceTestBase.php b/core/modules/user/tests/src/Functional/Rest/UserResourceTestBase.php
index d8fe60e40c..0b0f912418 100644
--- a/core/modules/user/tests/src/Functional/Rest/UserResourceTestBase.php
+++ b/core/modules/user/tests/src/Functional/Rest/UserResourceTestBase.php
@@ -15,7 +15,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/Rest/UserXmlBasicAuthTest.php b/core/modules/user/tests/src/Functional/Rest/UserXmlBasicAuthTest.php
index fc985980c3..d5065ff860 100644
--- a/core/modules/user/tests/src/Functional/Rest/UserXmlBasicAuthTest.php
+++ b/core/modules/user/tests/src/Functional/Rest/UserXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class UserXmlBasicAuthTest extends UserResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/UserAccountLinksTest.php b/core/modules/user/tests/src/Functional/UserAccountLinksTest.php
index c09fc34daf..678dfc5e86 100644
--- a/core/modules/user/tests/src/Functional/UserAccountLinksTest.php
+++ b/core/modules/user/tests/src/Functional/UserAccountLinksTest.php
@@ -16,7 +16,7 @@ class UserAccountLinksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'block', 'test_page_test'];
+  protected static $modules = ['menu_ui', 'block', 'test_page_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/UserAdminTest.php b/core/modules/user/tests/src/Functional/UserAdminTest.php
index 82e5df807c..022569b0d6 100644
--- a/core/modules/user/tests/src/Functional/UserAdminTest.php
+++ b/core/modules/user/tests/src/Functional/UserAdminTest.php
@@ -22,7 +22,7 @@ class UserAdminTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'views'];
+  protected static $modules = ['taxonomy', 'views'];
 
   /**
    * Registers a user and deletes it.
diff --git a/core/modules/user/tests/src/Functional/UserCacheTagsTest.php b/core/modules/user/tests/src/Functional/UserCacheTagsTest.php
index c9ab91fac7..a2eb542734 100644
--- a/core/modules/user/tests/src/Functional/UserCacheTagsTest.php
+++ b/core/modules/user/tests/src/Functional/UserCacheTagsTest.php
@@ -17,7 +17,7 @@ class UserCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/UserCancelTest.php b/core/modules/user/tests/src/Functional/UserCancelTest.php
index 869cd37bdd..3b10197d4c 100644
--- a/core/modules/user/tests/src/Functional/UserCancelTest.php
+++ b/core/modules/user/tests/src/Functional/UserCancelTest.php
@@ -22,7 +22,7 @@ class UserCancelTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/user/tests/src/Functional/UserCreateFailMailTest.php b/core/modules/user/tests/src/Functional/UserCreateFailMailTest.php
index 38f2514a49..5c23f4ba00 100644
--- a/core/modules/user/tests/src/Functional/UserCreateFailMailTest.php
+++ b/core/modules/user/tests/src/Functional/UserCreateFailMailTest.php
@@ -16,7 +16,7 @@ class UserCreateFailMailTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_mail_failure_test'];
+  protected static $modules = ['system_mail_failure_test'];
 
   /**
    * Tests the create user administration page.
diff --git a/core/modules/user/tests/src/Functional/UserEntityCallbacksTest.php b/core/modules/user/tests/src/Functional/UserEntityCallbacksTest.php
index feea805afd..e3626a94dd 100644
--- a/core/modules/user/tests/src/Functional/UserEntityCallbacksTest.php
+++ b/core/modules/user/tests/src/Functional/UserEntityCallbacksTest.php
@@ -18,7 +18,7 @@ class UserEntityCallbacksTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'user_hooks_test'];
+  protected static $modules = ['user', 'user_hooks_test'];
 
   /**
    * An authenticated user to use for testing.
diff --git a/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php b/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
index 6f493418b2..2c736c8496 100644
--- a/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
+++ b/core/modules/user/tests/src/Functional/UserLanguageCreationTest.php
@@ -18,7 +18,7 @@ class UserLanguageCreationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'language'];
+  protected static $modules = ['user', 'language'];
 
   /**
    * Functional test for language handling during user creation.
diff --git a/core/modules/user/tests/src/Functional/UserLanguageTest.php b/core/modules/user/tests/src/Functional/UserLanguageTest.php
index 0e6c0f1a75..8553017d1d 100644
--- a/core/modules/user/tests/src/Functional/UserLanguageTest.php
+++ b/core/modules/user/tests/src/Functional/UserLanguageTest.php
@@ -17,7 +17,7 @@ class UserLanguageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'language'];
+  protected static $modules = ['user', 'language'];
 
   /**
    * Test if user can change their default language.
diff --git a/core/modules/user/tests/src/Functional/UserLoginHttpTest.php b/core/modules/user/tests/src/Functional/UserLoginHttpTest.php
index b12a72b58e..0e8a9078c7 100644
--- a/core/modules/user/tests/src/Functional/UserLoginHttpTest.php
+++ b/core/modules/user/tests/src/Functional/UserLoginHttpTest.php
@@ -28,7 +28,7 @@ class UserLoginHttpTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * The cookie jar.
diff --git a/core/modules/user/tests/src/Functional/UserRoleAdminTest.php b/core/modules/user/tests/src/Functional/UserRoleAdminTest.php
index 24dc0849fc..4af9dd3125 100644
--- a/core/modules/user/tests/src/Functional/UserRoleAdminTest.php
+++ b/core/modules/user/tests/src/Functional/UserRoleAdminTest.php
@@ -25,7 +25,7 @@ class UserRoleAdminTest extends BrowserTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/UserSearchTest.php b/core/modules/user/tests/src/Functional/UserSearchTest.php
index 8ce0319bf6..ef7cd22005 100644
--- a/core/modules/user/tests/src/Functional/UserSearchTest.php
+++ b/core/modules/user/tests/src/Functional/UserSearchTest.php
@@ -17,7 +17,7 @@ class UserSearchTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['search'];
+  protected static $modules = ['search'];
 
   public function testUserSearch() {
     // Verify that a user without 'administer users' permission cannot search
diff --git a/core/modules/user/tests/src/Functional/UserTimeZoneTest.php b/core/modules/user/tests/src/Functional/UserTimeZoneTest.php
index ccf43253de..335a5592ab 100644
--- a/core/modules/user/tests/src/Functional/UserTimeZoneTest.php
+++ b/core/modules/user/tests/src/Functional/UserTimeZoneTest.php
@@ -17,7 +17,7 @@ class UserTimeZoneTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'system_test'];
+  protected static $modules = ['node', 'system_test'];
 
   /**
    * Tests the display of dates and time when user-configurable time zones are set.
diff --git a/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php b/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
index e272b60732..9cf2202a8e 100644
--- a/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
+++ b/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
@@ -21,7 +21,7 @@ class UserTokenReplaceTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'user_hooks_test'];
+  protected static $modules = ['language', 'user_hooks_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Functional/UserTranslationUITest.php b/core/modules/user/tests/src/Functional/UserTranslationUITest.php
index 630e58586c..657515e4ef 100644
--- a/core/modules/user/tests/src/Functional/UserTranslationUITest.php
+++ b/core/modules/user/tests/src/Functional/UserTranslationUITest.php
@@ -23,7 +23,7 @@ class UserTranslationUITest extends ContentTranslationUITestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'content_translation', 'user', 'views'];
+  protected static $modules = ['language', 'content_translation', 'user', 'views'];
 
   protected function setUp() {
     $this->entityTypeId = 'user';
diff --git a/core/modules/user/tests/src/Functional/Views/AccessTestBase.php b/core/modules/user/tests/src/Functional/Views/AccessTestBase.php
index 36f2334f11..350dfc7553 100644
--- a/core/modules/user/tests/src/Functional/Views/AccessTestBase.php
+++ b/core/modules/user/tests/src/Functional/Views/AccessTestBase.php
@@ -12,7 +12,7 @@
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Contains a user object that has no special permissions.
diff --git a/core/modules/user/tests/src/Functional/Views/BulkFormAccessTest.php b/core/modules/user/tests/src/Functional/Views/BulkFormAccessTest.php
index 5f613f3b16..e8c4831003 100644
--- a/core/modules/user/tests/src/Functional/Views/BulkFormAccessTest.php
+++ b/core/modules/user/tests/src/Functional/Views/BulkFormAccessTest.php
@@ -19,7 +19,7 @@ class BulkFormAccessTest extends UserTestBase {
    *
    * @var array
    */
-  public static $modules = ['user_access_test'];
+  protected static $modules = ['user_access_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/user/tests/src/Functional/Views/BulkFormTest.php b/core/modules/user/tests/src/Functional/Views/BulkFormTest.php
index 29c0e83e6b..b3baff7d31 100644
--- a/core/modules/user/tests/src/Functional/Views/BulkFormTest.php
+++ b/core/modules/user/tests/src/Functional/Views/BulkFormTest.php
@@ -19,7 +19,7 @@ class BulkFormTest extends UserTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui'];
+  protected static $modules = ['views_ui'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/user/tests/src/Functional/Views/FilterPermissionUiTest.php b/core/modules/user/tests/src/Functional/Views/FilterPermissionUiTest.php
index d08c2f3169..d8eba69498 100644
--- a/core/modules/user/tests/src/Functional/Views/FilterPermissionUiTest.php
+++ b/core/modules/user/tests/src/Functional/Views/FilterPermissionUiTest.php
@@ -25,7 +25,7 @@ class FilterPermissionUiTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'user_test_views', 'views_ui'];
+  protected static $modules = ['user', 'user_test_views', 'views_ui'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/user/tests/src/Functional/Views/HandlerFilterUserNameTest.php b/core/modules/user/tests/src/Functional/Views/HandlerFilterUserNameTest.php
index a5d271092a..a50eeebc44 100644
--- a/core/modules/user/tests/src/Functional/Views/HandlerFilterUserNameTest.php
+++ b/core/modules/user/tests/src/Functional/Views/HandlerFilterUserNameTest.php
@@ -19,7 +19,7 @@ class HandlerFilterUserNameTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'user_test_views'];
+  protected static $modules = ['views_ui', 'user_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/user/tests/src/Functional/Views/UserChangedTest.php b/core/modules/user/tests/src/Functional/Views/UserChangedTest.php
index 2271c0ce07..c31d4c359a 100644
--- a/core/modules/user/tests/src/Functional/Views/UserChangedTest.php
+++ b/core/modules/user/tests/src/Functional/Views/UserChangedTest.php
@@ -17,7 +17,7 @@ class UserChangedTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'user_test_views'];
+  protected static $modules = ['views_ui', 'user_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/user/tests/src/Functional/Views/UserFieldsAccessChangeTest.php b/core/modules/user/tests/src/Functional/Views/UserFieldsAccessChangeTest.php
index 1a238579c9..1a5601424c 100644
--- a/core/modules/user/tests/src/Functional/Views/UserFieldsAccessChangeTest.php
+++ b/core/modules/user/tests/src/Functional/Views/UserFieldsAccessChangeTest.php
@@ -14,7 +14,7 @@ class UserFieldsAccessChangeTest extends UserTestBase {
    *
    * @var array
    */
-  public static $modules = ['user_access_test'];
+  protected static $modules = ['user_access_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/user/tests/src/Functional/Views/UserTestBase.php b/core/modules/user/tests/src/Functional/Views/UserTestBase.php
index 49de6f793f..83f0ab297d 100644
--- a/core/modules/user/tests/src/Functional/Views/UserTestBase.php
+++ b/core/modules/user/tests/src/Functional/Views/UserTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['user_test_views', 'node'];
+  protected static $modules = ['user_test_views', 'node'];
 
   /**
    * Users to use during this test.
diff --git a/core/modules/user/tests/src/FunctionalJavascript/RegistrationWithUserFieldsTest.php b/core/modules/user/tests/src/FunctionalJavascript/RegistrationWithUserFieldsTest.php
index 29306cd4d1..8eda240588 100644
--- a/core/modules/user/tests/src/FunctionalJavascript/RegistrationWithUserFieldsTest.php
+++ b/core/modules/user/tests/src/FunctionalJavascript/RegistrationWithUserFieldsTest.php
@@ -31,7 +31,7 @@ class RegistrationWithUserFieldsTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_test'];
+  protected static $modules = ['field_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php b/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
index d6923faf97..64a12a7ce6 100644
--- a/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
+++ b/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
@@ -48,7 +48,7 @@ class UserRoleConditionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php b/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
index 6beecb88d3..e91f4fe7aa 100644
--- a/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
+++ b/core/modules/user/tests/src/Kernel/Field/UserNameFormatterTest.php
@@ -19,7 +19,7 @@ class UserNameFormatterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'user', 'system'];
+  protected static $modules = ['field', 'user', 'system'];
 
   /**
    * @var string
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserAdminPassTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserAdminPassTest.php
index 85cd761bc3..a54f797555 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserAdminPassTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserAdminPassTest.php
@@ -24,7 +24,7 @@ class MigrateUserAdminPassTest extends MigrateTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityDisplayTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityDisplayTest.php
index 0d3bb7c206..8a4f1a16b8 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityDisplayTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityDisplayTest.php
@@ -15,7 +15,7 @@ class MigrateUserPictureEntityDisplayTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file', 'image'];
+  protected static $modules = ['file', 'image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityFormDisplayTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityFormDisplayTest.php
index f75382496f..f501012fcc 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityFormDisplayTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureEntityFormDisplayTest.php
@@ -12,7 +12,7 @@
  */
 class MigrateUserPictureEntityFormDisplayTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['image', 'file'];
+  protected static $modules = ['image', 'file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldInstanceTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldInstanceTest.php
index 9b3829e06d..e9a8e62769 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldInstanceTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldInstanceTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateUserPictureFieldInstanceTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['image', 'file'];
+  protected static $modules = ['image', 'file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldTest.php
index 1389693024..fac8122c72 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserPictureFieldTest.php
@@ -13,7 +13,7 @@
  */
 class MigrateUserPictureFieldTest extends MigrateDrupal7TestBase {
 
-  public static $modules = ['image', 'file'];
+  protected static $modules = ['image', 'file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserProfileFieldInstanceTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserProfileFieldInstanceTest.php
index ecc9bc9651..c2a5bd5b36 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserProfileFieldInstanceTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserProfileFieldInstanceTest.php
@@ -15,7 +15,7 @@ class MigrateUserProfileFieldInstanceTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field'];
+  protected static $modules = ['field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserStubTest.php b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserStubTest.php
index 768f5d72c8..3c25c70cda 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/MigrateUserStubTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/MigrateUserStubTest.php
@@ -17,7 +17,7 @@ class MigrateUserStubTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserContactSettingsTest.php b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserContactSettingsTest.php
index fcdaa25426..b1e3ac11e1 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserContactSettingsTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserContactSettingsTest.php
@@ -14,7 +14,7 @@ class MigrateUserContactSettingsTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserProfileValuesTest.php b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserProfileValuesTest.php
index 71acad69f2..df807fe63d 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserProfileValuesTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserProfileValuesTest.php
@@ -15,7 +15,7 @@ class MigrateUserProfileValuesTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
index ed287770ae..b87708d3ce 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/d6/MigrateUserTest.php
@@ -22,7 +22,7 @@ class MigrateUserTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserTest.php b/core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserTest.php
index 7564fceeca..8ae31d740a 100644
--- a/core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserTest.php
+++ b/core/modules/user/tests/src/Kernel/Migrate/d7/MigrateUserTest.php
@@ -22,7 +22,7 @@ class MigrateUserTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'comment',
     'content_translation',
     'datetime',
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/ProfileFieldTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/ProfileFieldTest.php
index 99c61fd491..c24a0a79e2 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/ProfileFieldTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/ProfileFieldTest.php
@@ -15,7 +15,7 @@ class ProfileFieldTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/UserPictureInstanceTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/UserPictureInstanceTest.php
index d9e77edde0..a87ede1f7a 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/UserPictureInstanceTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/UserPictureInstanceTest.php
@@ -15,7 +15,7 @@ class UserPictureInstanceTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldValuesTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldValuesTest.php
index 26c2ed55f8..2e3aba4224 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldValuesTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/ProfileFieldValuesTest.php
@@ -15,7 +15,7 @@ class ProfileFieldValuesTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/RoleTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/RoleTest.php
index 1a841d32df..d37659b4f8 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/RoleTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/RoleTest.php
@@ -15,7 +15,7 @@ class RoleTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureFileTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureFileTest.php
index 2724d35f59..c77b45cc6f 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureFileTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureFileTest.php
@@ -15,7 +15,7 @@ class UserPictureFileTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureTest.php
index aea6afa7c9..2eb61d84c1 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserPictureTest.php
@@ -15,7 +15,7 @@ class UserPictureTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserTest.php
index 1dc34a7cd6..19f85be63a 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d6/UserTest.php
@@ -15,7 +15,7 @@ class UserTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/RoleTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/RoleTest.php
index d2d43a44c9..885894c780 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/RoleTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/RoleTest.php
@@ -15,7 +15,7 @@ class RoleTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migrate_drupal', 'user'];
+  protected static $modules = ['migrate_drupal', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserEntityTranslationTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserEntityTranslationTest.php
index e265ace618..d8d5d72242 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserEntityTranslationTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserEntityTranslationTest.php
@@ -16,7 +16,7 @@ class UserEntityTranslationTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserTest.php
index 80935715eb..09cdce70ae 100644
--- a/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserTest.php
+++ b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserTest.php
@@ -15,7 +15,7 @@ class UserTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'migrate_drupal'];
+  protected static $modules = ['user', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php b/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
index ae9d4cb13e..6a7aed7e08 100644
--- a/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
+++ b/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
@@ -22,7 +22,7 @@ class TempStoreDatabaseTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * A key/value store factory.
diff --git a/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
index fe967b2d9f..1ce92f0d66 100644
--- a/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
+++ b/core/modules/user/tests/src/Kernel/UserAccountFormFieldsTest.php
@@ -18,7 +18,7 @@ class UserAccountFormFieldsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   /**
    * Tests the root user account form section in the "Configure site" form.
diff --git a/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
index dfafb1d536..d6e5c353c0 100644
--- a/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
+++ b/core/modules/user/tests/src/Kernel/UserActionConfigSchemaTest.php
@@ -21,7 +21,7 @@ class UserActionConfigSchemaTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * Tests whether the user action config schema are valid.
diff --git a/core/modules/user/tests/src/Kernel/UserEntityTest.php b/core/modules/user/tests/src/Kernel/UserEntityTest.php
index 73fe869ec3..a05c6484b0 100644
--- a/core/modules/user/tests/src/Kernel/UserEntityTest.php
+++ b/core/modules/user/tests/src/Kernel/UserEntityTest.php
@@ -19,7 +19,7 @@ class UserEntityTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/UserFieldsTest.php b/core/modules/user/tests/src/Kernel/UserFieldsTest.php
index 672ddb065e..ee5bf39598 100644
--- a/core/modules/user/tests/src/Kernel/UserFieldsTest.php
+++ b/core/modules/user/tests/src/Kernel/UserFieldsTest.php
@@ -17,7 +17,7 @@ class UserFieldsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/UserInstallTest.php b/core/modules/user/tests/src/Kernel/UserInstallTest.php
index be3336f780..b95094736b 100644
--- a/core/modules/user/tests/src/Kernel/UserInstallTest.php
+++ b/core/modules/user/tests/src/Kernel/UserInstallTest.php
@@ -16,7 +16,7 @@ class UserInstallTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php b/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
index cac470aaab..ee7f881d11 100644
--- a/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
+++ b/core/modules/user/tests/src/Kernel/UserRoleDeleteTest.php
@@ -17,7 +17,7 @@ class UserRoleDeleteTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/user/tests/src/Kernel/UserRoleEntityTest.php b/core/modules/user/tests/src/Kernel/UserRoleEntityTest.php
index 562ada11f2..b597c3ddae 100644
--- a/core/modules/user/tests/src/Kernel/UserRoleEntityTest.php
+++ b/core/modules/user/tests/src/Kernel/UserRoleEntityTest.php
@@ -10,7 +10,7 @@
  */
 class UserRoleEntityTest extends KernelTestBase {
 
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   public function testOrderOfPermissions() {
     $role = Role::create(['id' => 'test_role']);
diff --git a/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php b/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
index 17364c059d..093c6bf67e 100644
--- a/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
+++ b/core/modules/user/tests/src/Kernel/UserSaveStatusTest.php
@@ -17,7 +17,7 @@ class UserSaveStatusTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/user/tests/src/Kernel/UserServiceProviderFallbackTest.php b/core/modules/user/tests/src/Kernel/UserServiceProviderFallbackTest.php
index 78ab454981..e5cbf27806 100644
--- a/core/modules/user/tests/src/Kernel/UserServiceProviderFallbackTest.php
+++ b/core/modules/user/tests/src/Kernel/UserServiceProviderFallbackTest.php
@@ -18,7 +18,7 @@ class UserServiceProviderFallbackTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Tests that user.tempstore.expire equals tempstore.expire if not customized.
diff --git a/core/modules/user/tests/src/Kernel/UserServiceProviderTest.php b/core/modules/user/tests/src/Kernel/UserServiceProviderTest.php
index 38f1af1d48..07f76c676d 100644
--- a/core/modules/user/tests/src/Kernel/UserServiceProviderTest.php
+++ b/core/modules/user/tests/src/Kernel/UserServiceProviderTest.php
@@ -18,7 +18,7 @@ class UserServiceProviderTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Tests that tempstore.expire is set to user.tempstore.expire.
diff --git a/core/modules/user/tests/src/Kernel/UserValidationTest.php b/core/modules/user/tests/src/Kernel/UserValidationTest.php
index 98065f36b4..144fa83811 100644
--- a/core/modules/user/tests/src/Kernel/UserValidationTest.php
+++ b/core/modules/user/tests/src/Kernel/UserValidationTest.php
@@ -21,7 +21,7 @@ class UserValidationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'user', 'system'];
+  protected static $modules = ['field', 'user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/Views/UserKernelTestBase.php b/core/modules/user/tests/src/Kernel/Views/UserKernelTestBase.php
index 0e862c86b8..dc6cd31879 100644
--- a/core/modules/user/tests/src/Kernel/Views/UserKernelTestBase.php
+++ b/core/modules/user/tests/src/Kernel/Views/UserKernelTestBase.php
@@ -15,7 +15,7 @@
    *
    * @var array
    */
-  public static $modules = ['user_test_views', 'user', 'system', 'field'];
+  protected static $modules = ['user_test_views', 'user', 'system', 'field'];
 
   /**
    * Users to use during this test.
diff --git a/core/modules/user/tests/src/Kernel/Views/UserViewsFieldAccessTest.php b/core/modules/user/tests/src/Kernel/Views/UserViewsFieldAccessTest.php
index f14779e26b..e20a01ba33 100644
--- a/core/modules/user/tests/src/Kernel/Views/UserViewsFieldAccessTest.php
+++ b/core/modules/user/tests/src/Kernel/Views/UserViewsFieldAccessTest.php
@@ -16,7 +16,7 @@ class UserViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'entity_test', 'language'];
+  protected static $modules = ['user', 'entity_test', 'language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php b/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
index 02844a1610..60403f966c 100644
--- a/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
+++ b/core/modules/user/tests/src/Kernel/WhosOnlineBlockTest.php
@@ -16,7 +16,7 @@ class WhosOnlineBlockTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'block', 'views'];
+  protected static $modules = ['system', 'user', 'block', 'views'];
 
   /**
    * The block being tested.
diff --git a/core/modules/views/src/Tests/FieldApiDataTest.php b/core/modules/views/src/Tests/FieldApiDataTest.php
index b20a8712e6..287adff732 100644
--- a/core/modules/views/src/Tests/FieldApiDataTest.php
+++ b/core/modules/views/src/Tests/FieldApiDataTest.php
@@ -21,7 +21,7 @@ class FieldApiDataTest extends FieldTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/src/Tests/Plugin/DisplayFeedTest.php b/core/modules/views/src/Tests/Plugin/DisplayFeedTest.php
index 04ba4cab99..5d162355e1 100644
--- a/core/modules/views/src/Tests/Plugin/DisplayFeedTest.php
+++ b/core/modules/views/src/Tests/Plugin/DisplayFeedTest.php
@@ -24,7 +24,7 @@ class DisplayFeedTest extends PluginTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'views'];
+  protected static $modules = ['block', 'node', 'views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php b/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php
index 66a8bc826b..5516df3d05 100644
--- a/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php
+++ b/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php
@@ -22,7 +22,7 @@ class StyleOpmlTest extends PluginTestBase {
    *
    * @var array
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/src/Tests/ViewKernelTestBase.php b/core/modules/views/src/Tests/ViewKernelTestBase.php
index 5a23285918..452d24ea2d 100644
--- a/core/modules/views/src/Tests/ViewKernelTestBase.php
+++ b/core/modules/views/src/Tests/ViewKernelTestBase.php
@@ -26,7 +26,7 @@
    *
    * @var array
    */
-  public static $modules = ['system', 'views', 'views_test_config', 'views_test_data', 'user'];
+  protected static $modules = ['system', 'views', 'views_test_config', 'views_test_data', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/src/Tests/ViewTestBase.php b/core/modules/views/src/Tests/ViewTestBase.php
index e1e5190f59..9db2136e78 100644
--- a/core/modules/views/src/Tests/ViewTestBase.php
+++ b/core/modules/views/src/Tests/ViewTestBase.php
@@ -30,7 +30,7 @@
    *
    * @var array
    */
-  public static $modules = ['views', 'views_test_config'];
+  protected static $modules = ['views', 'views_test_config'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp();
diff --git a/core/modules/views/src/Tests/Wizard/WizardTestBase.php b/core/modules/views/src/Tests/Wizard/WizardTestBase.php
index 29b96d38c1..404af4d6e4 100644
--- a/core/modules/views/src/Tests/Wizard/WizardTestBase.php
+++ b/core/modules/views/src/Tests/Wizard/WizardTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block', 'rest'];
+  protected static $modules = ['node', 'views_ui', 'block', 'rest'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/DefaultViewsTest.php b/core/modules/views/tests/src/Functional/DefaultViewsTest.php
index b6120707d9..8a591d3122 100644
--- a/core/modules/views/tests/src/Functional/DefaultViewsTest.php
+++ b/core/modules/views/tests/src/Functional/DefaultViewsTest.php
@@ -28,7 +28,7 @@ class DefaultViewsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'node', 'search', 'comment', 'taxonomy', 'block', 'user'];
+  protected static $modules = ['views', 'node', 'search', 'comment', 'taxonomy', 'block', 'user'];
 
   /**
    * An array of argument arrays to use for default views.
diff --git a/core/modules/views/tests/src/Functional/Entity/BaseFieldAccessTest.php b/core/modules/views/tests/src/Functional/Entity/BaseFieldAccessTest.php
index 19aa191e14..876d1aba8a 100644
--- a/core/modules/views/tests/src/Functional/Entity/BaseFieldAccessTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/BaseFieldAccessTest.php
@@ -25,7 +25,7 @@ class BaseFieldAccessTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'views', 'views_test_config', 'entity_test', 'node', 'views_entity_test',
   ];
 
diff --git a/core/modules/views/tests/src/Functional/Entity/FieldEntityTest.php b/core/modules/views/tests/src/Functional/Entity/FieldEntityTest.php
index 2393b6d269..e9cdf2c9c4 100644
--- a/core/modules/views/tests/src/Functional/Entity/FieldEntityTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/FieldEntityTest.php
@@ -31,7 +31,7 @@ class FieldEntityTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Entity/FieldEntityTranslationTest.php b/core/modules/views/tests/src/Functional/Entity/FieldEntityTranslationTest.php
index 2a227c5433..3d62103a53 100644
--- a/core/modules/views/tests/src/Functional/Entity/FieldEntityTranslationTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/FieldEntityTranslationTest.php
@@ -19,7 +19,7 @@ class FieldEntityTranslationTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'locale', 'content_translation', 'node'];
+  protected static $modules = ['language', 'locale', 'content_translation', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Entity/FilterEntityBundleTest.php b/core/modules/views/tests/src/Functional/Entity/FilterEntityBundleTest.php
index 22bb6435c8..80a7e12584 100644
--- a/core/modules/views/tests/src/Functional/Entity/FilterEntityBundleTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/FilterEntityBundleTest.php
@@ -26,7 +26,7 @@ class FilterEntityBundleTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Entity bundle data.
diff --git a/core/modules/views/tests/src/Functional/Entity/LatestRevisionFilterTest.php b/core/modules/views/tests/src/Functional/Entity/LatestRevisionFilterTest.php
index d73a11793b..3d978001cf 100644
--- a/core/modules/views/tests/src/Functional/Entity/LatestRevisionFilterTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/LatestRevisionFilterTest.php
@@ -40,7 +40,7 @@ class LatestRevisionFilterTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Entity/ViewNonTranslatableEntityTest.php b/core/modules/views/tests/src/Functional/Entity/ViewNonTranslatableEntityTest.php
index 911cd61e66..0b9d011608 100644
--- a/core/modules/views/tests/src/Functional/Entity/ViewNonTranslatableEntityTest.php
+++ b/core/modules/views/tests/src/Functional/Entity/ViewNonTranslatableEntityTest.php
@@ -18,7 +18,7 @@ class ViewNonTranslatableEntityTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'content_translation',
     'language_test',
diff --git a/core/modules/views/tests/src/Functional/GlossaryTest.php b/core/modules/views/tests/src/Functional/GlossaryTest.php
index ed247f1829..aed04d6285 100644
--- a/core/modules/views/tests/src/Functional/GlossaryTest.php
+++ b/core/modules/views/tests/src/Functional/GlossaryTest.php
@@ -21,7 +21,7 @@ class GlossaryTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Tests the default glossary view.
diff --git a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonAnonTest.php b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonAnonTest.php
index 134b00f223..e02ce83a9b 100644
--- a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonAnonTest.php
+++ b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class ViewHalJsonAnonTest extends ViewResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonBasicAuthTest.php b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonBasicAuthTest.php
index 87c39852cf..bf353b19f6 100644
--- a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonBasicAuthTest.php
+++ b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class ViewHalJsonBasicAuthTest extends ViewResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonCookieTest.php b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonCookieTest.php
index aa5aa4f6b7..f0b87c2423 100644
--- a/core/modules/views/tests/src/Functional/Hal/ViewHalJsonCookieTest.php
+++ b/core/modules/views/tests/src/Functional/Hal/ViewHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class ViewHalJsonCookieTest extends ViewResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Handler/AreaHTTPStatusCodeTest.php b/core/modules/views/tests/src/Functional/Handler/AreaHTTPStatusCodeTest.php
index dc914ce219..82923c9b2b 100644
--- a/core/modules/views/tests/src/Functional/Handler/AreaHTTPStatusCodeTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/AreaHTTPStatusCodeTest.php
@@ -25,7 +25,7 @@ class AreaHTTPStatusCodeTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Tests the area handler.
diff --git a/core/modules/views/tests/src/Functional/Handler/AreaTest.php b/core/modules/views/tests/src/Functional/Handler/AreaTest.php
index 1827319bbd..2a24374764 100644
--- a/core/modules/views/tests/src/Functional/Handler/AreaTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/AreaTest.php
@@ -27,7 +27,7 @@ class AreaTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui'];
+  protected static $modules = ['node', 'views_ui'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Handler/ArgumentStringTest.php b/core/modules/views/tests/src/Functional/Handler/ArgumentStringTest.php
index 17ece944c5..a1a57f719f 100644
--- a/core/modules/views/tests/src/Functional/Handler/ArgumentStringTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/ArgumentStringTest.php
@@ -24,7 +24,7 @@ class ArgumentStringTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Tests the glossary feature.
diff --git a/core/modules/views/tests/src/Functional/Handler/FieldDropButtonTest.php b/core/modules/views/tests/src/Functional/Handler/FieldDropButtonTest.php
index e0e380b0f8..b3c2b8051e 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldDropButtonTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldDropButtonTest.php
@@ -24,7 +24,7 @@ class FieldDropButtonTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Handler/FieldEntityOperationsTest.php b/core/modules/views/tests/src/Functional/Handler/FieldEntityOperationsTest.php
index 7ced4f7071..028973c4a7 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldEntityOperationsTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldEntityOperationsTest.php
@@ -26,7 +26,7 @@ class FieldEntityOperationsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'language', 'views_ui'];
+  protected static $modules = ['node', 'language', 'views_ui'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsTest.php b/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsTest.php
index d38ba41792..b2d96adf50 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsTest.php
@@ -30,7 +30,7 @@ class FieldGroupRowsTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'field_test'];
+  protected static $modules = ['node', 'field_test'];
 
   /**
    * Field that will be created to test the group/ungroup rows functionality
diff --git a/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsWebTest.php b/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsWebTest.php
index 275960cb0d..0efbd5166b 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsWebTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldGroupRowsWebTest.php
@@ -26,7 +26,7 @@ class FieldGroupRowsWebTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * The page node type.
diff --git a/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php b/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php
index eda5b81abe..a5d0fb9093 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php
@@ -30,7 +30,7 @@ class FieldWebTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Maps between the key in the expected result and the query result.
diff --git a/core/modules/views/tests/src/Functional/Handler/FilterDateTest.php b/core/modules/views/tests/src/Functional/Handler/FilterDateTest.php
index ec3b52385f..6e52bac4d6 100644
--- a/core/modules/views/tests/src/Functional/Handler/FilterDateTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FilterDateTest.php
@@ -29,7 +29,7 @@ class FilterDateTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'datetime'];
+  protected static $modules = ['node', 'views_ui', 'datetime'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Handler/FilterPlaceholderTextTest.php b/core/modules/views/tests/src/Functional/Handler/FilterPlaceholderTextTest.php
index 7d852f7c87..81f6826add 100644
--- a/core/modules/views/tests/src/Functional/Handler/FilterPlaceholderTextTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FilterPlaceholderTextTest.php
@@ -21,7 +21,7 @@ class FilterPlaceholderTextTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Tests that HTML placeholders are added, when appropriate.
diff --git a/core/modules/views/tests/src/Functional/Handler/HandlerAllTest.php b/core/modules/views/tests/src/Functional/Handler/HandlerAllTest.php
index 1a37ce8307..b81ef29af2 100644
--- a/core/modules/views/tests/src/Functional/Handler/HandlerAllTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/HandlerAllTest.php
@@ -23,7 +23,7 @@ class HandlerAllTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'aggregator',
     'book',
     'block',
diff --git a/core/modules/views/tests/src/Functional/Handler/HandlerTest.php b/core/modules/views/tests/src/Functional/Handler/HandlerTest.php
index cffe6d1402..1522f8d76f 100644
--- a/core/modules/views/tests/src/Functional/Handler/HandlerTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/HandlerTest.php
@@ -30,7 +30,7 @@ class HandlerTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'comment', 'node'];
+  protected static $modules = ['views_ui', 'comment', 'node'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/AccessTest.php b/core/modules/views/tests/src/Functional/Plugin/AccessTest.php
index 31a64cc1cf..31ab4abcfa 100644
--- a/core/modules/views/tests/src/Functional/Plugin/AccessTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/AccessTest.php
@@ -27,7 +27,7 @@ class AccessTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Web user for testing.
diff --git a/core/modules/views/tests/src/Functional/Plugin/ArgumentDefaultTest.php b/core/modules/views/tests/src/Functional/Plugin/ArgumentDefaultTest.php
index b12e43e857..bde1361999 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ArgumentDefaultTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ArgumentDefaultTest.php
@@ -35,7 +35,7 @@ class ArgumentDefaultTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block'];
+  protected static $modules = ['node', 'views_ui', 'block'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/CacheTagTest.php b/core/modules/views/tests/src/Functional/Plugin/CacheTagTest.php
index 1d78204db9..79273d0c26 100644
--- a/core/modules/views/tests/src/Functional/Plugin/CacheTagTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/CacheTagTest.php
@@ -27,7 +27,7 @@ class CacheTagTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * The node storage.
diff --git a/core/modules/views/tests/src/Functional/Plugin/CacheWebTest.php b/core/modules/views/tests/src/Functional/Plugin/CacheWebTest.php
index c919bcb831..67996aa852 100644
--- a/core/modules/views/tests/src/Functional/Plugin/CacheWebTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/CacheWebTest.php
@@ -29,7 +29,7 @@ class CacheWebTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Plugin/ContextualFiltersBlockContextTest.php b/core/modules/views/tests/src/Functional/Plugin/ContextualFiltersBlockContextTest.php
index 41356b69c7..722fc82935 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ContextualFiltersBlockContextTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ContextualFiltersBlockContextTest.php
@@ -21,7 +21,7 @@ class ContextualFiltersBlockContextTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test_views', 'views_ui', 'node'];
+  protected static $modules = ['block', 'block_test_views', 'views_ui', 'node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisabledDisplayTest.php b/core/modules/views/tests/src/Functional/Plugin/DisabledDisplayTest.php
index 708ac55030..7b00ea53fc 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisabledDisplayTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisabledDisplayTest.php
@@ -24,7 +24,7 @@ class DisabledDisplayTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'views'];
+  protected static $modules = ['block', 'node', 'views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisplayAttachmentTest.php b/core/modules/views/tests/src/Functional/Plugin/DisplayAttachmentTest.php
index 44668447c7..a8d3153b04 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisplayAttachmentTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisplayAttachmentTest.php
@@ -25,7 +25,7 @@ class DisplayAttachmentTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views'];
+  protected static $modules = ['node', 'views'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisplayEntityReferenceTest.php b/core/modules/views/tests/src/Functional/Plugin/DisplayEntityReferenceTest.php
index 499d1b2c8a..8b757dc694 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisplayEntityReferenceTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisplayEntityReferenceTest.php
@@ -32,7 +32,7 @@ class DisplayEntityReferenceTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field', 'views_ui'];
+  protected static $modules = ['entity_test', 'field', 'views_ui'];
 
   /**
    * The used field name in the test.
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisplayPageWebTest.php b/core/modules/views/tests/src/Functional/Plugin/DisplayPageWebTest.php
index 501d9226ee..c31698a1b1 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisplayPageWebTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisplayPageWebTest.php
@@ -27,7 +27,7 @@ class DisplayPageWebTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['menu_ui', 'block', 'views_ui'];
+  protected static $modules = ['menu_ui', 'block', 'views_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php b/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
index d8deaa598b..c0a99576c3 100644
--- a/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
@@ -26,7 +26,7 @@ class DisplayTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'node', 'block'];
+  protected static $modules = ['views_ui', 'node', 'block'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp();
diff --git a/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php b/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php
index f5901a080d..5546d86c64 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php
@@ -27,7 +27,7 @@ class ExposedFormCheckboxesTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views_ui', 'taxonomy'];
+  protected static $modules = ['node', 'views_ui', 'taxonomy'];
 
   /**
    * Test terms.
diff --git a/core/modules/views/tests/src/Functional/Plugin/ExposedFormTest.php b/core/modules/views/tests/src/Functional/Plugin/ExposedFormTest.php
index 4cd81d2891..eff3af036c 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ExposedFormTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ExposedFormTest.php
@@ -31,7 +31,7 @@ class ExposedFormTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block', 'entity_test'];
+  protected static $modules = ['node', 'views_ui', 'block', 'entity_test'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/FilterTest.php b/core/modules/views/tests/src/Functional/Plugin/FilterTest.php
index 60424108f5..6cf285e3e3 100644
--- a/core/modules/views/tests/src/Functional/Plugin/FilterTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/FilterTest.php
@@ -26,7 +26,7 @@ class FilterTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'node'];
+  protected static $modules = ['views_ui', 'node'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/MenuLinkTest.php b/core/modules/views/tests/src/Functional/Plugin/MenuLinkTest.php
index 8afbb57b8c..c452084300 100644
--- a/core/modules/views/tests/src/Functional/Plugin/MenuLinkTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/MenuLinkTest.php
@@ -24,7 +24,7 @@ class MenuLinkTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'views_ui', 'user', 'node', 'menu_ui', 'block'];
+  protected static $modules = ['views', 'views_ui', 'user', 'node', 'menu_ui', 'block'];
 
   /**
    * A user with permission to administer views, menus and view content.
diff --git a/core/modules/views/tests/src/Functional/Plugin/MiniPagerTest.php b/core/modules/views/tests/src/Functional/Plugin/MiniPagerTest.php
index 492d22f987..d8d7507b26 100644
--- a/core/modules/views/tests/src/Functional/Plugin/MiniPagerTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/MiniPagerTest.php
@@ -25,7 +25,7 @@ class MiniPagerTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * Nodes used by the test.
diff --git a/core/modules/views/tests/src/Functional/Plugin/NumericFormatPluralTest.php b/core/modules/views/tests/src/Functional/Plugin/NumericFormatPluralTest.php
index 08f2504c54..e72a2b2b58 100644
--- a/core/modules/views/tests/src/Functional/Plugin/NumericFormatPluralTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/NumericFormatPluralTest.php
@@ -18,7 +18,7 @@ class NumericFormatPluralTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'file', 'language', 'locale'];
+  protected static $modules = ['views_ui', 'file', 'language', 'locale'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Functional/Plugin/PagerTest.php b/core/modules/views/tests/src/Functional/Plugin/PagerTest.php
index 272a3f073d..cc64b6ef1d 100644
--- a/core/modules/views/tests/src/Functional/Plugin/PagerTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/PagerTest.php
@@ -28,7 +28,7 @@ class PagerTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui'];
+  protected static $modules = ['node', 'views_ui'];
 
   /**
    * String translation storage object.
diff --git a/core/modules/views/tests/src/Functional/Plugin/StyleSummaryTest.php b/core/modules/views/tests/src/Functional/Plugin/StyleSummaryTest.php
index a2359b9734..77674e2ff4 100644
--- a/core/modules/views/tests/src/Functional/Plugin/StyleSummaryTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/StyleSummaryTest.php
@@ -15,7 +15,7 @@ class StyleSummaryTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'views_ui'];
+  protected static $modules = ['entity_test', 'views_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Plugin/ViewsBulkTest.php b/core/modules/views/tests/src/Functional/Plugin/ViewsBulkTest.php
index e3faa88405..ae0d5cbc5f 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ViewsBulkTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ViewsBulkTest.php
@@ -23,7 +23,7 @@ class ViewsBulkTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'views'];
+  protected static $modules = ['node', 'views'];
 
   public function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/Functional/Plugin/ViewsFormTest.php b/core/modules/views/tests/src/Functional/Plugin/ViewsFormTest.php
index 3f6e1eca5f..9ad5e43918 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ViewsFormTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ViewsFormTest.php
@@ -16,7 +16,7 @@ class ViewsFormTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['action_bulk_test'];
+  protected static $modules = ['action_bulk_test'];
 
   /**
    * Tests the Views form wrapper.
diff --git a/core/modules/views/tests/src/Functional/RenderCacheWebTest.php b/core/modules/views/tests/src/Functional/RenderCacheWebTest.php
index f8dfdd810d..c297b7ea85 100644
--- a/core/modules/views/tests/src/Functional/RenderCacheWebTest.php
+++ b/core/modules/views/tests/src/Functional/RenderCacheWebTest.php
@@ -14,7 +14,7 @@ class RenderCacheWebTest extends ViewTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'block'];
+  protected static $modules = ['node', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Rest/ViewJsonBasicAuthTest.php b/core/modules/views/tests/src/Functional/Rest/ViewJsonBasicAuthTest.php
index 4ebe08c336..80f96132a3 100644
--- a/core/modules/views/tests/src/Functional/Rest/ViewJsonBasicAuthTest.php
+++ b/core/modules/views/tests/src/Functional/Rest/ViewJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class ViewJsonBasicAuthTest extends ViewResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Rest/ViewResourceTestBase.php b/core/modules/views/tests/src/Functional/Rest/ViewResourceTestBase.php
index b57256365e..f5dcf3e623 100644
--- a/core/modules/views/tests/src/Functional/Rest/ViewResourceTestBase.php
+++ b/core/modules/views/tests/src/Functional/Rest/ViewResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Rest/ViewXmlBasicAuthTest.php b/core/modules/views/tests/src/Functional/Rest/ViewXmlBasicAuthTest.php
index ba9e58b3e6..a3af943dab 100644
--- a/core/modules/views/tests/src/Functional/Rest/ViewXmlBasicAuthTest.php
+++ b/core/modules/views/tests/src/Functional/Rest/ViewXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class ViewXmlBasicAuthTest extends ViewResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/SearchIntegrationTest.php b/core/modules/views/tests/src/Functional/SearchIntegrationTest.php
index fbbc96582b..479581b75d 100644
--- a/core/modules/views/tests/src/Functional/SearchIntegrationTest.php
+++ b/core/modules/views/tests/src/Functional/SearchIntegrationTest.php
@@ -19,7 +19,7 @@ class SearchIntegrationTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'search'];
+  protected static $modules = ['node', 'search'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Functional/SearchMultilingualTest.php b/core/modules/views/tests/src/Functional/SearchMultilingualTest.php
index d6a72bf8cd..1849306fa8 100644
--- a/core/modules/views/tests/src/Functional/SearchMultilingualTest.php
+++ b/core/modules/views/tests/src/Functional/SearchMultilingualTest.php
@@ -20,7 +20,7 @@ class SearchMultilingualTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'search', 'language', 'content_translation'];
+  protected static $modules = ['node', 'search', 'language', 'content_translation'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Functional/TaxonomyGlossaryTest.php b/core/modules/views/tests/src/Functional/TaxonomyGlossaryTest.php
index fbf5f41458..1f7a4c630a 100644
--- a/core/modules/views/tests/src/Functional/TaxonomyGlossaryTest.php
+++ b/core/modules/views/tests/src/Functional/TaxonomyGlossaryTest.php
@@ -18,7 +18,7 @@ class TaxonomyGlossaryTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Functional/ViewTestBase.php b/core/modules/views/tests/src/Functional/ViewTestBase.php
index 10bc5d48bc..ec499ae369 100644
--- a/core/modules/views/tests/src/Functional/ViewTestBase.php
+++ b/core/modules/views/tests/src/Functional/ViewTestBase.php
@@ -28,7 +28,7 @@
    *
    * @var array
    */
-  public static $modules = ['views', 'views_test_config'];
+  protected static $modules = ['views', 'views_test_config'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp();
diff --git a/core/modules/views/tests/src/Functional/ViewsEscapingTest.php b/core/modules/views/tests/src/Functional/ViewsEscapingTest.php
index 80a8398722..90443ba36d 100644
--- a/core/modules/views/tests/src/Functional/ViewsEscapingTest.php
+++ b/core/modules/views/tests/src/Functional/ViewsEscapingTest.php
@@ -25,7 +25,7 @@ class ViewsEscapingTest extends ViewTestBase {
    *
    * @see \Drupal\simpletest\WebTestBase::setup()
    */
-  public static $modules = ['views', 'theme_test'];
+  protected static $modules = ['views', 'theme_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/ViewsThemeIntegrationTest.php b/core/modules/views/tests/src/Functional/ViewsThemeIntegrationTest.php
index 9bdb405b86..4db8a0f027 100644
--- a/core/modules/views/tests/src/Functional/ViewsThemeIntegrationTest.php
+++ b/core/modules/views/tests/src/Functional/ViewsThemeIntegrationTest.php
@@ -28,7 +28,7 @@ class ViewsThemeIntegrationTest extends ViewTestBase {
    *
    * @see \Drupal\simpletest\WebTestBase::setup()
    */
-  public static $modules = ['views', 'theme_test'];
+  protected static $modules = ['views', 'theme_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Functional/Wizard/TaggedWithTest.php b/core/modules/views/tests/src/Functional/Wizard/TaggedWithTest.php
index 680d64496e..7067a6bcd1 100644
--- a/core/modules/views/tests/src/Functional/Wizard/TaggedWithTest.php
+++ b/core/modules/views/tests/src/Functional/Wizard/TaggedWithTest.php
@@ -21,7 +21,7 @@ class TaggedWithTest extends WizardTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Node type with an autocomplete tagging field.
diff --git a/core/modules/views/tests/src/Functional/Wizard/WizardTestBase.php b/core/modules/views/tests/src/Functional/Wizard/WizardTestBase.php
index 0178c08c25..924db29c60 100644
--- a/core/modules/views/tests/src/Functional/Wizard/WizardTestBase.php
+++ b/core/modules/views/tests/src/Functional/Wizard/WizardTestBase.php
@@ -14,7 +14,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block', 'rest'];
+  protected static $modules = ['node', 'views_ui', 'block', 'rest'];
 
   protected function setUp($import_test_views = TRUE) {
     parent::setUp($import_test_views);
diff --git a/core/modules/views/tests/src/FunctionalJavascript/ClickSortingAJAXTest.php b/core/modules/views/tests/src/FunctionalJavascript/ClickSortingAJAXTest.php
index 085fd821d5..1a73eeeab8 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/ClickSortingAJAXTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/ClickSortingAJAXTest.php
@@ -20,7 +20,7 @@ class ClickSortingAJAXTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_test_config'];
+  protected static $modules = ['node', 'views', 'views_test_config'];
 
   public static $testViews = ['test_content_ajax'];
 
diff --git a/core/modules/views/tests/src/FunctionalJavascript/ExposedFilterAJAXTest.php b/core/modules/views/tests/src/FunctionalJavascript/ExposedFilterAJAXTest.php
index c6cbaf5764..a229eeddad 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/ExposedFilterAJAXTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/ExposedFilterAJAXTest.php
@@ -19,7 +19,7 @@ class ExposedFilterAJAXTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_test_modal'];
+  protected static $modules = ['node', 'views', 'views_test_modal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php b/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php
index d4760e59b4..3703664613 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php
@@ -22,7 +22,7 @@ class GlossaryViewTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'node', 'views', 'views_test_config'];
+  protected static $modules = ['language', 'node', 'views', 'views_test_config'];
 
   /**
    * @var array
diff --git a/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php b/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php
index de4efd24ab..6d37995daf 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php
@@ -20,7 +20,7 @@ class PaginationAJAXTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_test_config'];
+  protected static $modules = ['node', 'views', 'views_test_config'];
 
   /**
    * @var array
diff --git a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/ContextualFilterTest.php b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/ContextualFilterTest.php
index f0ac608548..360d4c4c39 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/ContextualFilterTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/ContextualFilterTest.php
@@ -15,7 +15,7 @@ class ContextualFilterTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui', 'views_test_config'];
+  protected static $modules = ['node', 'views', 'views_ui', 'views_test_config'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/FieldTest.php b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/FieldTest.php
index 079fe99ee4..410c9e2f13 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/FieldTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/FieldTest.php
@@ -19,7 +19,7 @@ class FieldTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui', 'views_test_config'];
+  protected static $modules = ['node', 'views', 'views_ui', 'views_test_config'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/GroupedExposedFilterTest.php b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/GroupedExposedFilterTest.php
index 1bc8a486d3..e4ab1335c9 100644
--- a/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/GroupedExposedFilterTest.php
+++ b/core/modules/views/tests/src/FunctionalJavascript/Plugin/views/Handler/GroupedExposedFilterTest.php
@@ -17,7 +17,7 @@ class GroupedExposedFilterTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui', 'user', 'views_test_config'];
+  protected static $modules = ['node', 'views', 'views_ui', 'user', 'views_test_config'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Entity/EntityViewsWithMultivalueBasefieldTest.php b/core/modules/views/tests/src/Kernel/Entity/EntityViewsWithMultivalueBasefieldTest.php
index edf0fb0e10..3a5014f64c 100644
--- a/core/modules/views/tests/src/Kernel/Entity/EntityViewsWithMultivalueBasefieldTest.php
+++ b/core/modules/views/tests/src/Kernel/Entity/EntityViewsWithMultivalueBasefieldTest.php
@@ -16,7 +16,7 @@ class EntityViewsWithMultivalueBasefieldTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Entity/RowEntityRenderersTest.php b/core/modules/views/tests/src/Kernel/Entity/RowEntityRenderersTest.php
index a110f00209..961de7928c 100644
--- a/core/modules/views/tests/src/Kernel/Entity/RowEntityRenderersTest.php
+++ b/core/modules/views/tests/src/Kernel/Entity/RowEntityRenderersTest.php
@@ -21,7 +21,7 @@ class RowEntityRenderersTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'filter', 'text', 'node', 'user', 'language', 'views_test_language'];
+  protected static $modules = ['field', 'filter', 'text', 'node', 'user', 'language', 'views_test_language'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php b/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php
index 34f58122ca..46dce37482 100644
--- a/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php
+++ b/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php
@@ -29,7 +29,7 @@ class ViewEntityDependenciesTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment', 'user', 'field', 'text', 'search'];
+  protected static $modules = ['node', 'comment', 'user', 'field', 'text', 'search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/EventSubscriber/ViewsEntitySchemaSubscriberIntegrationTest.php b/core/modules/views/tests/src/Kernel/EventSubscriber/ViewsEntitySchemaSubscriberIntegrationTest.php
index 24e4e6af51..04306b56a1 100644
--- a/core/modules/views/tests/src/Kernel/EventSubscriber/ViewsEntitySchemaSubscriberIntegrationTest.php
+++ b/core/modules/views/tests/src/Kernel/EventSubscriber/ViewsEntitySchemaSubscriberIntegrationTest.php
@@ -26,7 +26,7 @@ class ViewsEntitySchemaSubscriberIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'entity_test_update', 'user', 'text'];
+  protected static $modules = ['entity_test', 'entity_test_update', 'user', 'text'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/AreaEmptyTest.php b/core/modules/views/tests/src/Kernel/Handler/AreaEmptyTest.php
index a113f0c4ff..1b1be514e6 100644
--- a/core/modules/views/tests/src/Kernel/Handler/AreaEmptyTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/AreaEmptyTest.php
@@ -16,7 +16,7 @@ class AreaEmptyTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/AreaEntityTest.php b/core/modules/views/tests/src/Kernel/Handler/AreaEntityTest.php
index 672e63d2d8..9de113b69a 100644
--- a/core/modules/views/tests/src/Kernel/Handler/AreaEntityTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/AreaEntityTest.php
@@ -24,7 +24,7 @@ class AreaEntityTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'user', 'block'];
+  protected static $modules = ['entity_test', 'user', 'block'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/AreaOrderTest.php b/core/modules/views/tests/src/Kernel/Handler/AreaOrderTest.php
index 84a66ab5c8..e670eab6c1 100644
--- a/core/modules/views/tests/src/Kernel/Handler/AreaOrderTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/AreaOrderTest.php
@@ -21,7 +21,7 @@ class AreaOrderTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'block'];
+  protected static $modules = ['user', 'block'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/AreaTextTest.php b/core/modules/views/tests/src/Kernel/Handler/AreaTextTest.php
index 2feaaf144e..0cf95c37e4 100644
--- a/core/modules/views/tests/src/Kernel/Handler/AreaTextTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/AreaTextTest.php
@@ -13,7 +13,7 @@
  */
 class AreaTextTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system', 'user', 'filter'];
+  protected static $modules = ['system', 'user', 'filter'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/AreaViewTest.php b/core/modules/views/tests/src/Kernel/Handler/AreaViewTest.php
index a3ab52960b..2b57885e62 100644
--- a/core/modules/views/tests/src/Kernel/Handler/AreaViewTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/AreaViewTest.php
@@ -18,7 +18,7 @@ class AreaViewTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/ComputedFieldTest.php b/core/modules/views/tests/src/Kernel/Handler/ComputedFieldTest.php
index ed00f68a06..336c5c2b62 100644
--- a/core/modules/views/tests/src/Kernel/Handler/ComputedFieldTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/ComputedFieldTest.php
@@ -26,7 +26,7 @@ class ComputedFieldTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php b/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php
index ee219ab7a4..e485d16c21 100644
--- a/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php
@@ -14,7 +14,7 @@ class EntityTestViewsFieldAccessTest extends FieldFieldAccessTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldCounterTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldCounterTest.php
index dbd04d8337..26de19f0c3 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldCounterTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldCounterTest.php
@@ -17,7 +17,7 @@ class FieldCounterTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldDropbuttonTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldDropbuttonTest.php
index b789bd62ad..ffc1a80e21 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldDropbuttonTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldDropbuttonTest.php
@@ -29,7 +29,7 @@ class FieldDropbuttonTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
     'node',
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldEntityLinkTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldEntityLinkTest.php
index a7f5116f35..065c78c987 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldEntityLinkTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldEntityLinkTest.php
@@ -30,7 +30,7 @@ class FieldEntityLinkTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'entity_test'];
+  protected static $modules = ['user', 'entity_test'];
 
   /**
    * An admin user account.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldFieldAccessTestBase.php b/core/modules/views/tests/src/Kernel/Handler/FieldFieldAccessTestBase.php
index 5ff77bc9f4..37e1f4effe 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldFieldAccessTestBase.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldFieldAccessTestBase.php
@@ -30,7 +30,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldFieldTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldFieldTest.php
index a738dcf5e3..b89df7a0f4 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldFieldTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldFieldTest.php
@@ -24,7 +24,7 @@ class FieldFieldTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'entity_test', 'user', 'views_test_formatter', 'views_entity_test'];
+  protected static $modules = ['field', 'entity_test', 'user', 'views_test_formatter', 'views_entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php
index f3ea97ca18..0ed3ee66c4 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php
@@ -15,7 +15,7 @@
  */
 class FieldKernelTest extends ViewsKernelTestBase {
 
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldRenderedEntityTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldRenderedEntityTest.php
index 02419f4847..f49d682492 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldRenderedEntityTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldRenderedEntityTest.php
@@ -24,7 +24,7 @@ class FieldRenderedEntityTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field'];
+  protected static $modules = ['entity_test', 'field'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldUrlTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldUrlTest.php
index 0814402ca6..61d2cb5940 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FieldUrlTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FieldUrlTest.php
@@ -13,7 +13,7 @@
  */
 class FieldUrlTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorDefaultTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorDefaultTest.php
index 7beceb9bd9..cf4f1b15a1 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorDefaultTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorDefaultTest.php
@@ -16,7 +16,7 @@ class FilterBooleanOperatorDefaultTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'views_test_data'];
+  protected static $modules = ['system', 'views_test_data'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
index 325da5106e..5495ceaa43 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorStringTest.php
@@ -19,7 +19,7 @@ class FilterBooleanOperatorStringTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorTest.php
index 7cdd41f525..e653cbbf0e 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterBooleanOperatorTest.php
@@ -18,7 +18,7 @@ class FilterBooleanOperatorTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterCombineTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterCombineTest.php
index feffbafd9e..fb5c8e6853 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterCombineTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterCombineTest.php
@@ -15,7 +15,7 @@ class FilterCombineTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterEqualityTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterEqualityTest.php
index 4f8c4961e3..f9476beb9a 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterEqualityTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterEqualityTest.php
@@ -12,7 +12,7 @@
  */
 class FilterEqualityTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterInOperatorTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterInOperatorTest.php
index e02a8430c7..a78d0bb22a 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterInOperatorTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterInOperatorTest.php
@@ -12,7 +12,7 @@
  */
 class FilterInOperatorTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterNumericTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterNumericTest.php
index e1093e47f7..53b72f2e2d 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterNumericTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterNumericTest.php
@@ -12,7 +12,7 @@
  */
 class FilterNumericTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/FilterStringTest.php b/core/modules/views/tests/src/Kernel/Handler/FilterStringTest.php
index 5d8f71f172..bf6d9de387 100644
--- a/core/modules/views/tests/src/Kernel/Handler/FilterStringTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/FilterStringTest.php
@@ -12,7 +12,7 @@
  */
 class FilterStringTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/HandlerAliasTest.php b/core/modules/views/tests/src/Kernel/Handler/HandlerAliasTest.php
index 53d25b38e6..16c0e19a50 100644
--- a/core/modules/views/tests/src/Kernel/Handler/HandlerAliasTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/HandlerAliasTest.php
@@ -12,7 +12,7 @@
  */
 class HandlerAliasTest extends ViewsKernelTestBase {
 
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Handler/SortTranslationTest.php b/core/modules/views/tests/src/Kernel/Handler/SortTranslationTest.php
index ac8000a8d8..9d4e2e10e1 100644
--- a/core/modules/views/tests/src/Kernel/Handler/SortTranslationTest.php
+++ b/core/modules/views/tests/src/Kernel/Handler/SortTranslationTest.php
@@ -19,7 +19,7 @@ class SortTranslationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'field',
     'language',
diff --git a/core/modules/views/tests/src/Kernel/ModuleTest.php b/core/modules/views/tests/src/Kernel/ModuleTest.php
index f61c856200..2127bd0e91 100644
--- a/core/modules/views/tests/src/Kernel/ModuleTest.php
+++ b/core/modules/views/tests/src/Kernel/ModuleTest.php
@@ -25,7 +25,7 @@ class ModuleTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'user', 'block'];
+  protected static $modules = ['field', 'user', 'block'];
 
   /**
    * Stores the last triggered error.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php b/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php
index 5b634afa1c..82411f63d7 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php
@@ -24,7 +24,7 @@ class BlockDependenciesTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'user', 'field'];
+  protected static $modules = ['node', 'block', 'user', 'field'];
 
   /**
    * Tests that exposed filter blocks have the correct dependencies.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/CacheTest.php b/core/modules/views/tests/src/Kernel/Plugin/CacheTest.php
index caa479b4a1..aa157e1cc0 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/CacheTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/CacheTest.php
@@ -28,7 +28,7 @@ class CacheTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'text', 'user', 'node'];
+  protected static $modules = ['taxonomy', 'text', 'user', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Plugin/Display/ViewsMenuLinkTest.php b/core/modules/views/tests/src/Kernel/Plugin/Display/ViewsMenuLinkTest.php
index a6776b585a..90a3d963e3 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/Display/ViewsMenuLinkTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/Display/ViewsMenuLinkTest.php
@@ -14,7 +14,7 @@ class ViewsMenuLinkTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_ui',
     'user',
     'views',
diff --git a/core/modules/views/tests/src/Kernel/Plugin/DisplayKernelTest.php b/core/modules/views/tests/src/Kernel/Plugin/DisplayKernelTest.php
index 69666cf342..64966239bf 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/DisplayKernelTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/DisplayKernelTest.php
@@ -24,7 +24,7 @@ class DisplayKernelTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'field', 'user'];
+  protected static $modules = ['block', 'node', 'field', 'user'];
 
   /**
    * Views plugin types to test.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/DisplayPageTest.php b/core/modules/views/tests/src/Kernel/Plugin/DisplayPageTest.php
index 3904cdb490..f946922c35 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/DisplayPageTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/DisplayPageTest.php
@@ -30,7 +30,7 @@ class DisplayPageTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'views_test_data'];
+  protected static $modules = ['system', 'user', 'field', 'views_test_data'];
 
   /**
    * The router dumper to get all routes.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php b/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php
index aa7b3cb335..ac436f2e5a 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php
@@ -23,7 +23,7 @@ class ExposedFormRenderTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Plugin/PagerKernelTest.php b/core/modules/views/tests/src/Kernel/Plugin/PagerKernelTest.php
index c6f581a655..891e013520 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/PagerKernelTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/PagerKernelTest.php
@@ -21,7 +21,7 @@ class PagerKernelTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'node'];
+  protected static $modules = ['user', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Plugin/RelationshipJoinTestBase.php b/core/modules/views/tests/src/Kernel/Plugin/RelationshipJoinTestBase.php
index 191024e470..ecb90a7f3f 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/RelationshipJoinTestBase.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/RelationshipJoinTestBase.php
@@ -18,7 +18,7 @@
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field'];
+  protected static $modules = ['system', 'user', 'field'];
 
   /**
    * @var \Drupal\user\Entity\User
diff --git a/core/modules/views/tests/src/Kernel/Plugin/RowEntityTest.php b/core/modules/views/tests/src/Kernel/Plugin/RowEntityTest.php
index 208a6f0ee3..599629a5fe 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/RowEntityTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/RowEntityTest.php
@@ -21,7 +21,7 @@ class RowEntityTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'text', 'filter', 'field', 'system', 'node', 'user'];
+  protected static $modules = ['taxonomy', 'text', 'filter', 'field', 'system', 'node', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/RowRenderCacheTest.php b/core/modules/views/tests/src/Kernel/Plugin/RowRenderCacheTest.php
index 223963e2d0..c0b022b18c 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/RowRenderCacheTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/RowRenderCacheTest.php
@@ -24,7 +24,7 @@ class RowRenderCacheTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'node'];
+  protected static $modules = ['user', 'node'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/SqlEntityLoadingTest.php b/core/modules/views/tests/src/Kernel/Plugin/SqlEntityLoadingTest.php
index b4d525a131..86f6437d77 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/SqlEntityLoadingTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/SqlEntityLoadingTest.php
@@ -19,7 +19,7 @@ class SqlEntityLoadingTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Plugin/StyleMappingTest.php b/core/modules/views/tests/src/Kernel/Plugin/StyleMappingTest.php
index d0683deb47..a3ae4ec9f6 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/StyleMappingTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/StyleMappingTest.php
@@ -11,7 +11,7 @@
  */
 class StyleMappingTest extends StyleTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/Plugin/ViewsBlockTest.php b/core/modules/views/tests/src/Kernel/Plugin/ViewsBlockTest.php
index 7c49327290..bde6a7f09b 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/ViewsBlockTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/ViewsBlockTest.php
@@ -19,7 +19,7 @@ class ViewsBlockTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test_views'];
+  protected static $modules = ['block', 'block_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/QueryGroupByTest.php b/core/modules/views/tests/src/Kernel/QueryGroupByTest.php
index 25d8b4a4c1..e4e272c81a 100644
--- a/core/modules/views/tests/src/Kernel/QueryGroupByTest.php
+++ b/core/modules/views/tests/src/Kernel/QueryGroupByTest.php
@@ -27,7 +27,7 @@ class QueryGroupByTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'system', 'field', 'user', 'language'];
+  protected static $modules = ['entity_test', 'system', 'field', 'user', 'language'];
 
   /**
    * The storage for the test entity type.
diff --git a/core/modules/views/tests/src/Kernel/RenderCacheIntegrationTest.php b/core/modules/views/tests/src/Kernel/RenderCacheIntegrationTest.php
index 02e90cd502..2168665de0 100644
--- a/core/modules/views/tests/src/Kernel/RenderCacheIntegrationTest.php
+++ b/core/modules/views/tests/src/Kernel/RenderCacheIntegrationTest.php
@@ -27,7 +27,7 @@ class RenderCacheIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'user', 'node'];
+  protected static $modules = ['entity_test', 'user', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/TestViewsTest.php b/core/modules/views/tests/src/Kernel/TestViewsTest.php
index dcd1859be3..1b21dfeaf8 100644
--- a/core/modules/views/tests/src/Kernel/TestViewsTest.php
+++ b/core/modules/views/tests/src/Kernel/TestViewsTest.php
@@ -22,7 +22,7 @@ class TestViewsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_test_data'];
+  protected static $modules = ['views_test_data'];
 
   /**
    * Tests default configuration data type.
diff --git a/core/modules/views/tests/src/Kernel/TokenReplaceTest.php b/core/modules/views/tests/src/Kernel/TokenReplaceTest.php
index 4b1cfc362c..76253f2823 100644
--- a/core/modules/views/tests/src/Kernel/TokenReplaceTest.php
+++ b/core/modules/views/tests/src/Kernel/TokenReplaceTest.php
@@ -12,7 +12,7 @@
  */
 class TokenReplaceTest extends ViewsKernelTestBase {
 
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/ViewExecutableTest.php b/core/modules/views/tests/src/Kernel/ViewExecutableTest.php
index 1290d54d85..5acc225547 100644
--- a/core/modules/views/tests/src/Kernel/ViewExecutableTest.php
+++ b/core/modules/views/tests/src/Kernel/ViewExecutableTest.php
@@ -31,7 +31,7 @@ class ViewExecutableTest extends ViewsKernelTestBase {
 
   use CommentTestTrait;
 
-  public static $modules = ['system', 'node', 'comment', 'user', 'filter', 'field', 'text'];
+  protected static $modules = ['system', 'node', 'comment', 'user', 'filter', 'field', 'text'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views/tests/src/Kernel/ViewsConfigDependenciesIntegrationTest.php b/core/modules/views/tests/src/Kernel/ViewsConfigDependenciesIntegrationTest.php
index 294bb0f44c..e82a546d40 100644
--- a/core/modules/views/tests/src/Kernel/ViewsConfigDependenciesIntegrationTest.php
+++ b/core/modules/views/tests/src/Kernel/ViewsConfigDependenciesIntegrationTest.php
@@ -18,7 +18,7 @@ class ViewsConfigDependenciesIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'file', 'image', 'entity_test', 'user', 'text'];
+  protected static $modules = ['field', 'file', 'image', 'entity_test', 'user', 'text'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php b/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php
index be9920eb31..fb3fc7a638 100644
--- a/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php
+++ b/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php
@@ -29,7 +29,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'views', 'views_test_config', 'views_test_data', 'user'];
+  protected static $modules = ['system', 'views', 'views_test_config', 'views_test_data', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/ViewsPreprocessTest.php b/core/modules/views/tests/src/Kernel/ViewsPreprocessTest.php
index ab8bc7704a..4dd6f2526b 100644
--- a/core/modules/views/tests/src/Kernel/ViewsPreprocessTest.php
+++ b/core/modules/views/tests/src/Kernel/ViewsPreprocessTest.php
@@ -20,7 +20,7 @@ class ViewsPreprocessTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'user', 'node'];
+  protected static $modules = ['entity_test', 'user', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Wizard/WizardPluginBaseKernelTest.php b/core/modules/views/tests/src/Kernel/Wizard/WizardPluginBaseKernelTest.php
index beb7b486d5..29844b58e9 100644
--- a/core/modules/views/tests/src/Kernel/Wizard/WizardPluginBaseKernelTest.php
+++ b/core/modules/views/tests/src/Kernel/Wizard/WizardPluginBaseKernelTest.php
@@ -20,7 +20,7 @@ class WizardPluginBaseKernelTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'system', 'user', 'views_ui'];
+  protected static $modules = ['language', 'system', 'user', 'views_ui'];
 
   /**
    * Contains thw wizard plugin manager.
diff --git a/core/modules/views_ui/src/Tests/UITestBase.php b/core/modules/views_ui/src/Tests/UITestBase.php
index 752be6e339..96644d8beb 100644
--- a/core/modules/views_ui/src/Tests/UITestBase.php
+++ b/core/modules/views_ui/src/Tests/UITestBase.php
@@ -31,7 +31,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block', 'taxonomy'];
+  protected static $modules = ['node', 'views_ui', 'block', 'taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/Functional/AnalyzeTest.php b/core/modules/views_ui/tests/src/Functional/AnalyzeTest.php
index 32d1ae9802..9ed2345341 100644
--- a/core/modules/views_ui/tests/src/Functional/AnalyzeTest.php
+++ b/core/modules/views_ui/tests/src/Functional/AnalyzeTest.php
@@ -14,7 +14,7 @@ class AnalyzeTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui'];
+  protected static $modules = ['views_ui'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views_ui/tests/src/Functional/AreaEntityUITest.php b/core/modules/views_ui/tests/src/Functional/AreaEntityUITest.php
index d74575fd46..41faa009a3 100644
--- a/core/modules/views_ui/tests/src/Functional/AreaEntityUITest.php
+++ b/core/modules/views_ui/tests/src/Functional/AreaEntityUITest.php
@@ -17,7 +17,7 @@ class AreaEntityUITest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   public function testUI() {
     // Set up a block and a entity_test entity.
diff --git a/core/modules/views_ui/tests/src/Functional/DisplayCRUDTest.php b/core/modules/views_ui/tests/src/Functional/DisplayCRUDTest.php
index c1c7cef441..d98bd46ee5 100644
--- a/core/modules/views_ui/tests/src/Functional/DisplayCRUDTest.php
+++ b/core/modules/views_ui/tests/src/Functional/DisplayCRUDTest.php
@@ -23,7 +23,7 @@ class DisplayCRUDTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['contextual'];
+  protected static $modules = ['contextual'];
 
   /**
    * Tests adding a display.
diff --git a/core/modules/views_ui/tests/src/Functional/DisplayFeedTest.php b/core/modules/views_ui/tests/src/Functional/DisplayFeedTest.php
index 9dba45010f..1230c12ae2 100644
--- a/core/modules/views_ui/tests/src/Functional/DisplayFeedTest.php
+++ b/core/modules/views_ui/tests/src/Functional/DisplayFeedTest.php
@@ -22,7 +22,7 @@ class DisplayFeedTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'aggregator'];
+  protected static $modules = ['views_ui', 'aggregator'];
 
   /**
    * Tests feed display admin UI.
diff --git a/core/modules/views_ui/tests/src/Functional/DisplayPathTest.php b/core/modules/views_ui/tests/src/Functional/DisplayPathTest.php
index 2f007f193c..5c1e7f3993 100644
--- a/core/modules/views_ui/tests/src/Functional/DisplayPathTest.php
+++ b/core/modules/views_ui/tests/src/Functional/DisplayPathTest.php
@@ -25,7 +25,7 @@ protected function setUp($import_test_views = TRUE) {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui'];
+  protected static $modules = ['menu_ui'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views_ui/tests/src/Functional/DisplayTest.php b/core/modules/views_ui/tests/src/Functional/DisplayTest.php
index 8fa5a80de3..10cbe5ac02 100644
--- a/core/modules/views_ui/tests/src/Functional/DisplayTest.php
+++ b/core/modules/views_ui/tests/src/Functional/DisplayTest.php
@@ -25,7 +25,7 @@ class DisplayTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['contextual'];
+  protected static $modules = ['contextual'];
 
   /**
    * Tests adding a display.
diff --git a/core/modules/views_ui/tests/src/Functional/ExposedFormUITest.php b/core/modules/views_ui/tests/src/Functional/ExposedFormUITest.php
index 0822eb833c..c45394b078 100644
--- a/core/modules/views_ui/tests/src/Functional/ExposedFormUITest.php
+++ b/core/modules/views_ui/tests/src/Functional/ExposedFormUITest.php
@@ -21,7 +21,7 @@ class ExposedFormUITest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views_ui', 'block', 'taxonomy', 'field_ui', 'datetime'];
+  protected static $modules = ['node', 'views_ui', 'block', 'taxonomy', 'field_ui', 'datetime'];
 
   /**
    * Array of error message strings raised by the grouped form.
diff --git a/core/modules/views_ui/tests/src/Functional/FilterUITest.php b/core/modules/views_ui/tests/src/Functional/FilterUITest.php
index 18ada1bca5..d831d05881 100644
--- a/core/modules/views_ui/tests/src/Functional/FilterUITest.php
+++ b/core/modules/views_ui/tests/src/Functional/FilterUITest.php
@@ -22,7 +22,7 @@ class FilterUITest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'node'];
+  protected static $modules = ['views_ui', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/Functional/HandlerTest.php b/core/modules/views_ui/tests/src/Functional/HandlerTest.php
index 7d96d0c5b5..ac3d7852b5 100644
--- a/core/modules/views_ui/tests/src/Functional/HandlerTest.php
+++ b/core/modules/views_ui/tests/src/Functional/HandlerTest.php
@@ -19,7 +19,7 @@ class HandlerTest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node_test_views'];
+  protected static $modules = ['node_test_views'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/views_ui/tests/src/Functional/NewViewConfigSchemaTest.php b/core/modules/views_ui/tests/src/Functional/NewViewConfigSchemaTest.php
index ef493ff8c8..0da216a5be 100644
--- a/core/modules/views_ui/tests/src/Functional/NewViewConfigSchemaTest.php
+++ b/core/modules/views_ui/tests/src/Functional/NewViewConfigSchemaTest.php
@@ -14,7 +14,7 @@ class NewViewConfigSchemaTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'node', 'comment', 'file', 'taxonomy', 'dblog', 'aggregator'];
+  protected static $modules = ['views_ui', 'node', 'comment', 'file', 'taxonomy', 'dblog', 'aggregator'];
 
   /**
    * Tests creating brand new views.
diff --git a/core/modules/views_ui/tests/src/Functional/ReportFieldsTest.php b/core/modules/views_ui/tests/src/Functional/ReportFieldsTest.php
index d2527d0b9d..5ffd7004c9 100644
--- a/core/modules/views_ui/tests/src/Functional/ReportFieldsTest.php
+++ b/core/modules/views_ui/tests/src/Functional/ReportFieldsTest.php
@@ -20,7 +20,7 @@ class ReportFieldsTest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Tests the Views fields report page.
diff --git a/core/modules/views_ui/tests/src/Functional/ReportTest.php b/core/modules/views_ui/tests/src/Functional/ReportTest.php
index e7979930c1..7cf4ed6413 100644
--- a/core/modules/views_ui/tests/src/Functional/ReportTest.php
+++ b/core/modules/views_ui/tests/src/Functional/ReportTest.php
@@ -14,7 +14,7 @@ class ReportTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'views_ui'];
+  protected static $modules = ['views', 'views_ui'];
 
   /**
    * Stores an admin user used by the different tests.
diff --git a/core/modules/views_ui/tests/src/Functional/StorageTest.php b/core/modules/views_ui/tests/src/Functional/StorageTest.php
index df3d030e70..96e61e251c 100644
--- a/core/modules/views_ui/tests/src/Functional/StorageTest.php
+++ b/core/modules/views_ui/tests/src/Functional/StorageTest.php
@@ -24,7 +24,7 @@ class StorageTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'language'];
+  protected static $modules = ['views_ui', 'language'];
 
   /**
    * Tests changing label, description and tag.
diff --git a/core/modules/views_ui/tests/src/Functional/TokenizeAreaUITest.php b/core/modules/views_ui/tests/src/Functional/TokenizeAreaUITest.php
index df42d8e11d..1c6941d873 100644
--- a/core/modules/views_ui/tests/src/Functional/TokenizeAreaUITest.php
+++ b/core/modules/views_ui/tests/src/Functional/TokenizeAreaUITest.php
@@ -16,7 +16,7 @@ class TokenizeAreaUITest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * Test that the right tokens are shown as available for replacement.
diff --git a/core/modules/views_ui/tests/src/Functional/TranslatedViewTest.php b/core/modules/views_ui/tests/src/Functional/TranslatedViewTest.php
index 7238ffad64..d85d74ae33 100644
--- a/core/modules/views_ui/tests/src/Functional/TranslatedViewTest.php
+++ b/core/modules/views_ui/tests/src/Functional/TranslatedViewTest.php
@@ -16,7 +16,7 @@ class TranslatedViewTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'views_ui',
   ];
diff --git a/core/modules/views_ui/tests/src/Functional/UITestBase.php b/core/modules/views_ui/tests/src/Functional/UITestBase.php
index db85773714..c5e28d4637 100644
--- a/core/modules/views_ui/tests/src/Functional/UITestBase.php
+++ b/core/modules/views_ui/tests/src/Functional/UITestBase.php
@@ -28,7 +28,7 @@
    *
    * @var array
    */
-  public static $modules = ['node', 'views_ui', 'block', 'taxonomy'];
+  protected static $modules = ['node', 'views_ui', 'block', 'taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/Functional/UnsavedPreviewTest.php b/core/modules/views_ui/tests/src/Functional/UnsavedPreviewTest.php
index 3265e1a2f5..fe8dd99d2c 100644
--- a/core/modules/views_ui/tests/src/Functional/UnsavedPreviewTest.php
+++ b/core/modules/views_ui/tests/src/Functional/UnsavedPreviewTest.php
@@ -26,7 +26,7 @@ class UnsavedPreviewTest extends UITestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views_ui'];
+  protected static $modules = ['node', 'views_ui'];
 
   /**
    * Sets up a Drupal site for running functional and integration tests.
diff --git a/core/modules/views_ui/tests/src/Functional/ViewsListTest.php b/core/modules/views_ui/tests/src/Functional/ViewsListTest.php
index 956ab9bc0c..d4633e7cf4 100644
--- a/core/modules/views_ui/tests/src/Functional/ViewsListTest.php
+++ b/core/modules/views_ui/tests/src/Functional/ViewsListTest.php
@@ -17,7 +17,7 @@ class ViewsListTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'views_ui'];
+  protected static $modules = ['block', 'views_ui'];
 
   /**
    * A user with permission to administer views.
diff --git a/core/modules/views_ui/tests/src/Functional/ViewsUITourTest.php b/core/modules/views_ui/tests/src/Functional/ViewsUITourTest.php
index 8a2dd2953f..3b3fb1c8ab 100644
--- a/core/modules/views_ui/tests/src/Functional/ViewsUITourTest.php
+++ b/core/modules/views_ui/tests/src/Functional/ViewsUITourTest.php
@@ -31,7 +31,7 @@ class ViewsUITourTest extends TourTestBase {
    *
    * @var array
    */
-  public static $modules = ['views_ui', 'tour', 'language', 'locale'];
+  protected static $modules = ['views_ui', 'tour', 'language', 'locale'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/views_ui/tests/src/Functional/XssTest.php b/core/modules/views_ui/tests/src/Functional/XssTest.php
index cabb48ebcf..49a467edad 100644
--- a/core/modules/views_ui/tests/src/Functional/XssTest.php
+++ b/core/modules/views_ui/tests/src/Functional/XssTest.php
@@ -14,7 +14,7 @@ class XssTest extends UITestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'user', 'views_ui', 'views_ui_test'];
+  protected static $modules = ['node', 'user', 'views_ui', 'views_ui_test'];
 
   public function testViewsUi() {
     $this->drupalGet('admin/structure/views/view/sa_contrib_2013_035');
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/DisplayTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/DisplayTest.php
index 7dcaccdd24..bfe16bcddc 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/DisplayTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/DisplayTest.php
@@ -19,7 +19,7 @@ class DisplayTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'contextual',
     'node',
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/FilterCriteriaTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterCriteriaTest.php
index 9e303dfb92..07966cea20 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/FilterCriteriaTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterCriteriaTest.php
@@ -14,7 +14,7 @@ class FilterCriteriaTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui'];
+  protected static $modules = ['node', 'views', 'views_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
index 6f2f625968..2d7571fd69 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
@@ -14,7 +14,7 @@ class FilterOptionsTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui', 'views_ui_test_field'];
+  protected static $modules = ['node', 'views', 'views_ui', 'views_ui_test_field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/LibraryCachingTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/LibraryCachingTest.php
index b1b158ba6c..5aab0af98b 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/LibraryCachingTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/LibraryCachingTest.php
@@ -14,7 +14,7 @@ class LibraryCachingTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui'];
+  protected static $modules = ['node', 'views', 'views_ui'];
 
   /**
    * Tests if the Views UI dialogs open on consecutive requests.
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsListingTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsListingTest.php
index fc696c03a8..a433deb005 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsListingTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsListingTest.php
@@ -15,7 +15,7 @@ class ViewsListingTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui'];
+  protected static $modules = ['node', 'views', 'views_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsWizardTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsWizardTest.php
index 16369f12fe..d446db83f0 100644
--- a/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsWizardTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/ViewsWizardTest.php
@@ -15,7 +15,7 @@ class ViewsWizardTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views', 'views_ui', 'block', 'user'];
+  protected static $modules = ['node', 'views', 'views_ui', 'block', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views_ui/tests/src/Kernel/TagTest.php b/core/modules/views_ui/tests/src/Kernel/TagTest.php
index 44d341776d..a61281263c 100644
--- a/core/modules/views_ui/tests/src/Kernel/TagTest.php
+++ b/core/modules/views_ui/tests/src/Kernel/TagTest.php
@@ -19,7 +19,7 @@ class TagTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['views', 'views_ui', 'user'];
+  protected static $modules = ['views', 'views_ui', 'user'];
 
   /**
    * Tests the views_ui_autocomplete_tag function.
diff --git a/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonAnonTest.php b/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonAnonTest.php
index 0c2fe00463..e36e296181 100644
--- a/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonAnonTest.php
+++ b/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class WorkflowHalJsonAnonTest extends WorkflowResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonBasicAuthTest.php b/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonBasicAuthTest.php
index b2e9807333..3c1632b67a 100644
--- a/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonBasicAuthTest.php
+++ b/core/modules/workflows/tests/src/Functional/Hal/WorkflowHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class WorkflowHalJsonBasicAuthTest extends WorkflowHalJsonAnonTest {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Functional/Rest/WorkflowJsonBasicAuthTest.php b/core/modules/workflows/tests/src/Functional/Rest/WorkflowJsonBasicAuthTest.php
index db687cfbb4..f906529aac 100644
--- a/core/modules/workflows/tests/src/Functional/Rest/WorkflowJsonBasicAuthTest.php
+++ b/core/modules/workflows/tests/src/Functional/Rest/WorkflowJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class WorkflowJsonBasicAuthTest extends WorkflowResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Functional/Rest/WorkflowResourceTestBase.php b/core/modules/workflows/tests/src/Functional/Rest/WorkflowResourceTestBase.php
index ce796a4f97..43c0765f76 100644
--- a/core/modules/workflows/tests/src/Functional/Rest/WorkflowResourceTestBase.php
+++ b/core/modules/workflows/tests/src/Functional/Rest/WorkflowResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'workflows',
     'workflow_type_test',
   ];
diff --git a/core/modules/workflows/tests/src/Functional/Rest/WorkflowXmlBasicAuthTest.php b/core/modules/workflows/tests/src/Functional/Rest/WorkflowXmlBasicAuthTest.php
index db443e4763..2147b9a3f0 100644
--- a/core/modules/workflows/tests/src/Functional/Rest/WorkflowXmlBasicAuthTest.php
+++ b/core/modules/workflows/tests/src/Functional/Rest/WorkflowXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class WorkflowXmlBasicAuthTest extends WorkflowResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Functional/WorkflowUiNoTypeTest.php b/core/modules/workflows/tests/src/Functional/WorkflowUiNoTypeTest.php
index 01c61ac6b0..cbf71ed883 100644
--- a/core/modules/workflows/tests/src/Functional/WorkflowUiNoTypeTest.php
+++ b/core/modules/workflows/tests/src/Functional/WorkflowUiNoTypeTest.php
@@ -16,7 +16,7 @@ class WorkflowUiNoTypeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['workflows', 'block'];
+  protected static $modules = ['workflows', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Functional/WorkflowUiTest.php b/core/modules/workflows/tests/src/Functional/WorkflowUiTest.php
index 227ddd769a..f04e5276b9 100644
--- a/core/modules/workflows/tests/src/Functional/WorkflowUiTest.php
+++ b/core/modules/workflows/tests/src/Functional/WorkflowUiTest.php
@@ -18,7 +18,7 @@ class WorkflowUiTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['workflows', 'workflow_type_test', 'block'];
+  protected static $modules = ['workflows', 'workflow_type_test', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workflows/tests/src/Kernel/ComplexWorkflowTypeTest.php b/core/modules/workflows/tests/src/Kernel/ComplexWorkflowTypeTest.php
index 15d27286ca..501675da89 100644
--- a/core/modules/workflows/tests/src/Kernel/ComplexWorkflowTypeTest.php
+++ b/core/modules/workflows/tests/src/Kernel/ComplexWorkflowTypeTest.php
@@ -17,7 +17,7 @@ class ComplexWorkflowTypeTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workflows', 'workflow_type_test'];
+  protected static $modules = ['workflows', 'workflow_type_test'];
 
   /**
    * @covers \Drupal\workflows\Entity\Workflow::loadMultipleByType
diff --git a/core/modules/workflows/tests/src/Kernel/PredefinedWorkflowTypeTest.php b/core/modules/workflows/tests/src/Kernel/PredefinedWorkflowTypeTest.php
index f3f0b5768b..2f294fd915 100644
--- a/core/modules/workflows/tests/src/Kernel/PredefinedWorkflowTypeTest.php
+++ b/core/modules/workflows/tests/src/Kernel/PredefinedWorkflowTypeTest.php
@@ -15,7 +15,7 @@ class PredefinedWorkflowTypeTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workflows', 'workflow_type_test'];
+  protected static $modules = ['workflows', 'workflow_type_test'];
 
   /**
    * Test a predefined workflow type.
diff --git a/core/modules/workflows/tests/src/Kernel/RequiredStatesTest.php b/core/modules/workflows/tests/src/Kernel/RequiredStatesTest.php
index 8d4edc9012..13d871822d 100644
--- a/core/modules/workflows/tests/src/Kernel/RequiredStatesTest.php
+++ b/core/modules/workflows/tests/src/Kernel/RequiredStatesTest.php
@@ -18,7 +18,7 @@ class RequiredStatesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workflows', 'workflow_type_test'];
+  protected static $modules = ['workflows', 'workflow_type_test'];
 
   /**
    * @covers ::getRequiredStates
diff --git a/core/modules/workflows/tests/src/Kernel/WorkflowAccessControlHandlerTest.php b/core/modules/workflows/tests/src/Kernel/WorkflowAccessControlHandlerTest.php
index cd4e7ceb14..c70b85936f 100644
--- a/core/modules/workflows/tests/src/Kernel/WorkflowAccessControlHandlerTest.php
+++ b/core/modules/workflows/tests/src/Kernel/WorkflowAccessControlHandlerTest.php
@@ -20,7 +20,7 @@ class WorkflowAccessControlHandlerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'workflows',
     'workflow_type_test',
     'system',
diff --git a/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php b/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
index c1070dc53c..bc6d270d70 100644
--- a/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
+++ b/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
@@ -17,7 +17,7 @@ class WorkflowDependenciesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'workflows', 'workflow_type_test', 'workflow_third_party_settings_test'];
+  protected static $modules = ['system', 'workflows', 'workflow_type_test', 'workflow_third_party_settings_test'];
 
   /**
    * Tests \Drupal\workflows\Entity\Workflow::onDependencyRemoval().
diff --git a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceJsonBasicAuthTest.php b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceJsonBasicAuthTest.php
index 8be512a793..73049690d4 100644
--- a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceJsonBasicAuthTest.php
+++ b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceJsonBasicAuthTest.php
@@ -16,7 +16,7 @@ class WorkspaceJsonBasicAuthTest extends WorkspaceResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
index 79f24da5a8..e0c732cf86 100644
--- a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
+++ b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceResourceTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workspaces'];
+  protected static $modules = ['workspaces'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceXmlBasicAuthTest.php b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceXmlBasicAuthTest.php
index 8769d9e8ba..af5e619a0b 100644
--- a/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceXmlBasicAuthTest.php
+++ b/core/modules/workspaces/tests/src/Functional/EntityResource/WorkspaceXmlBasicAuthTest.php
@@ -18,7 +18,7 @@ class WorkspaceXmlBasicAuthTest extends WorkspaceResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceBypassTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceBypassTest.php
index 162fc0ee72..276c13a478 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceBypassTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceBypassTest.php
@@ -18,7 +18,7 @@ class WorkspaceBypassTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user', 'block', 'workspaces'];
+  protected static $modules = ['node', 'user', 'block', 'workspaces'];
 
   /**
    * Verifies that a user can edit anything in a workspace they own.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceCacheContextTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceCacheContextTest.php
index f47ae7f544..b9dfa9e5c4 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceCacheContextTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceCacheContextTest.php
@@ -20,7 +20,7 @@ class WorkspaceCacheContextTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'node', 'workspaces'];
+  protected static $modules = ['block', 'node', 'workspaces'];
 
   /**
    * Tests the 'workspace' cache context.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceConcurrentEditingTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceConcurrentEditingTest.php
index 996e72decc..1c8c809662 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceConcurrentEditingTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceConcurrentEditingTest.php
@@ -17,7 +17,7 @@ class WorkspaceConcurrentEditingTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'node', 'workspaces'];
+  protected static $modules = ['block', 'node', 'workspaces'];
 
   /**
    * Test switching workspace via the switcher block and admin page.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspacePermissionsTest.php b/core/modules/workspaces/tests/src/Functional/WorkspacePermissionsTest.php
index 473a861c3f..6e72eae6e9 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspacePermissionsTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspacePermissionsTest.php
@@ -17,7 +17,7 @@ class WorkspacePermissionsTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workspaces'];
+  protected static $modules = ['workspaces'];
 
   /**
    * Verifies that a user can create but not edit a workspace.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceSwitcherTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceSwitcherTest.php
index ce0b3ed470..e83abe3d7c 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceSwitcherTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceSwitcherTest.php
@@ -18,7 +18,7 @@ class WorkspaceSwitcherTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block', 'workspaces'];
+  protected static $modules = ['block', 'workspaces'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceTest.php
index 5c7bea6e6a..38e5fd1f6a 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceTest.php
@@ -16,7 +16,7 @@ class WorkspaceTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workspaces'];
+  protected static $modules = ['workspaces'];
 
   /**
    * A test user.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspaceViewTest.php b/core/modules/workspaces/tests/src/Functional/WorkspaceViewTest.php
index df1b3c8c57..7fdc0f45a6 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspaceViewTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspaceViewTest.php
@@ -17,7 +17,7 @@ class WorkspaceViewTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workspaces'];
+  protected static $modules = ['workspaces'];
 
   /**
    * Verifies that a user can view their own workspace.
diff --git a/core/modules/workspaces/tests/src/Functional/WorkspacesUninstallTest.php b/core/modules/workspaces/tests/src/Functional/WorkspacesUninstallTest.php
index e652e3fc82..7f35fb1b81 100644
--- a/core/modules/workspaces/tests/src/Functional/WorkspacesUninstallTest.php
+++ b/core/modules/workspaces/tests/src/Functional/WorkspacesUninstallTest.php
@@ -19,7 +19,7 @@ class WorkspacesUninstallTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['workspaces'];
+  protected static $modules = ['workspaces'];
 
   /**
    * Tests deleting workspace entities and uninstalling Workspaces module.
diff --git a/core/modules/workspaces/tests/src/Kernel/WorkspaceCRUDTest.php b/core/modules/workspaces/tests/src/Kernel/WorkspaceCRUDTest.php
index 0d878ac083..95769399c6 100644
--- a/core/modules/workspaces/tests/src/Kernel/WorkspaceCRUDTest.php
+++ b/core/modules/workspaces/tests/src/Kernel/WorkspaceCRUDTest.php
@@ -43,7 +43,7 @@ class WorkspaceCRUDTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'user',
     'system',
     'workspaces',
diff --git a/core/modules/workspaces/tests/src/Kernel/WorkspaceInternalResourceTest.php b/core/modules/workspaces/tests/src/Kernel/WorkspaceInternalResourceTest.php
index 2c7758b962..9551b96f18 100644
--- a/core/modules/workspaces/tests/src/Kernel/WorkspaceInternalResourceTest.php
+++ b/core/modules/workspaces/tests/src/Kernel/WorkspaceInternalResourceTest.php
@@ -17,7 +17,7 @@ class WorkspaceInternalResourceTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'serialization', 'rest', 'workspaces'];
+  protected static $modules = ['user', 'serialization', 'rest', 'workspaces'];
 
   /**
    * Tests enabling workspace associations for REST throws an exception.
diff --git a/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php b/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
index 61656a86bd..2860f4d033 100644
--- a/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
+++ b/core/profiles/testing/modules/drupal_system_listing_compatible_test/tests/src/Kernel/SystemListingCrossProfileCompatibleTest.php
@@ -20,7 +20,7 @@ class SystemListingCrossProfileCompatibleTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['drupal_system_cross_profile_test'];
+  protected static $modules = ['drupal_system_cross_profile_test'];
 
   /**
    * Use the Minimal profile.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
index ffdbd98eb9..aba9e8e307 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
@@ -14,7 +14,7 @@ class AjaxCallbacksTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ajax_forms_test'];
+  protected static $modules = ['ajax_forms_test'];
 
   /**
    * Tests if Ajax callback works on date element.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormCacheTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormCacheTest.php
index 52e095267e..d5abd6c91d 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormCacheTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormCacheTest.php
@@ -17,7 +17,7 @@ class AjaxFormCacheTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ajax_test', 'ajax_forms_test'];
+  protected static $modules = ['ajax_test', 'ajax_forms_test'];
 
   /**
    * Tests the usage of form cache for AJAX forms.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
index bfd890a04f..3e7374ec00 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
@@ -14,7 +14,7 @@ class AjaxFormImageButtonTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ajax_forms_test'];
+  protected static $modules = ['ajax_forms_test'];
 
   /**
    * Tests image buttons can be operated with the keyboard ENTER key.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
index 5a167f729c..902d07891d 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
@@ -14,7 +14,7 @@ class AjaxFormPageCacheTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ajax_test', 'ajax_forms_test'];
+  protected static $modules = ['ajax_test', 'ajax_forms_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php
index 5d11ce49b4..24a19d2daf 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php
@@ -14,7 +14,7 @@ class AjaxTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ajax_test'];
+  protected static $modules = ['ajax_test'];
 
   public function testAjaxWithAdminRoute() {
     \Drupal::service('theme_installer')->install(['stable', 'seven']);
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/BackwardCompatibilityTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/BackwardCompatibilityTest.php
index 9a45583b7c..094cc8bf25 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/BackwardCompatibilityTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/BackwardCompatibilityTest.php
@@ -14,7 +14,7 @@ class BackwardCompatibilityTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'js_ajax_test',
   ];
 
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/ThrobberTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/ThrobberTest.php
index 56715e6dd1..24fa7b71b7 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/ThrobberTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/ThrobberTest.php
@@ -14,7 +14,7 @@ class ThrobberTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'views',
     'views_ui',
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php
index 1c76c26ea3..cc68d3add1 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php
@@ -16,7 +16,7 @@ class FormGroupingElementsTest extends WebDriverTestBase {
    *
    * @var array
    */
-  public static $modules = ['form_test'];
+  protected static $modules = ['form_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php
index 4396a8b6e3..e9f72cd2df 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php
@@ -19,7 +19,7 @@ class MachineNameTest extends WebDriverTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'form_test'];
+  protected static $modules = ['node', 'form_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Core/Session/SessionTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/Session/SessionTest.php
index f4a1800382..5b9e1b4b07 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/Session/SessionTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/Session/SessionTest.php
@@ -15,7 +15,7 @@ class SessionTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_link_content', 'block'];
+  protected static $modules = ['menu_link_content', 'block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php
index 4bfe3e0b3a..ef29a99a31 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php
@@ -14,7 +14,7 @@ class DialogPositionTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * Tests if the dialog UI works properly with block layout page.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php b/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php
index 3d0b402a48..4c1ed6d34b 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php
@@ -21,7 +21,7 @@ class EntityReferenceAutocompleteWidgetTest extends WebDriverTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php
index 6dd591f5fe..440a42ac1a 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php
@@ -17,7 +17,7 @@ class JSWebAssertTest extends WebDriverTestBase {
    *
    * @var array
    */
-  public static $modules = ['js_webassert_test'];
+  protected static $modules = ['js_webassert_test'];
 
   /**
    * Tests that JSWebAssert assertions work correctly.
diff --git a/core/tests/Drupal/FunctionalTests/Bootstrap/UncaughtExceptionTest.php b/core/tests/Drupal/FunctionalTests/Bootstrap/UncaughtExceptionTest.php
index 9885200808..c1baa540c6 100644
--- a/core/tests/Drupal/FunctionalTests/Bootstrap/UncaughtExceptionTest.php
+++ b/core/tests/Drupal/FunctionalTests/Bootstrap/UncaughtExceptionTest.php
@@ -37,7 +37,7 @@ class UncaughtExceptionTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['error_service_test'];
+  protected static $modules = ['error_service_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Breadcrumb/Breadcrumb404Test.php b/core/tests/Drupal/FunctionalTests/Breadcrumb/Breadcrumb404Test.php
index 7dcafbff85..cbf6b987a7 100644
--- a/core/tests/Drupal/FunctionalTests/Breadcrumb/Breadcrumb404Test.php
+++ b/core/tests/Drupal/FunctionalTests/Breadcrumb/Breadcrumb404Test.php
@@ -17,7 +17,7 @@ class Breadcrumb404Test extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'block'];
+  protected static $modules = ['system', 'block'];
 
   /**
    * Tests that different 404s don't create unnecessary cache entries.
diff --git a/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
index 9673b6f06c..b042d9f058 100644
--- a/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
+++ b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
@@ -23,7 +23,7 @@ class BrowserTestBaseTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['test_page_test', 'form_test', 'system_test', 'node'];
+  protected static $modules = ['test_page_test', 'form_test', 'system_test', 'node'];
 
   /**
    * Tests basic page test.
diff --git a/core/tests/Drupal/FunctionalTests/Core/Config/SchemaConfigListenerTest.php b/core/tests/Drupal/FunctionalTests/Core/Config/SchemaConfigListenerTest.php
index 698a7d1a03..262f58d387 100644
--- a/core/tests/Drupal/FunctionalTests/Core/Config/SchemaConfigListenerTest.php
+++ b/core/tests/Drupal/FunctionalTests/Core/Config/SchemaConfigListenerTest.php
@@ -17,6 +17,6 @@ class SchemaConfigListenerTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
 }
diff --git a/core/tests/Drupal/FunctionalTests/Datetime/TimestampTest.php b/core/tests/Drupal/FunctionalTests/Datetime/TimestampTest.php
index 8faf8c6c91..7259ac97d5 100644
--- a/core/tests/Drupal/FunctionalTests/Datetime/TimestampTest.php
+++ b/core/tests/Drupal/FunctionalTests/Datetime/TimestampTest.php
@@ -41,7 +41,7 @@ class TimestampTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'entity_test', 'field_ui'];
+  protected static $modules = ['node', 'entity_test', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php b/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php
index e8c8ae5e54..78d4024b13 100644
--- a/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php
+++ b/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest.php
@@ -31,7 +31,7 @@ class ContentEntityFormCorrectUserInputMappingOnFieldDeltaElementsTest extends B
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormFieldValidationFilteringTest.php b/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormFieldValidationFilteringTest.php
index ad8b4383bd..37ee858a74 100644
--- a/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormFieldValidationFilteringTest.php
+++ b/core/tests/Drupal/FunctionalTests/Entity/ContentEntityFormFieldValidationFilteringTest.php
@@ -48,7 +48,7 @@ class ContentEntityFormFieldValidationFilteringTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'field_test', 'file', 'image'];
+  protected static $modules = ['entity_test', 'field_test', 'file', 'image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Entity/DeleteMultipleFormTest.php b/core/tests/Drupal/FunctionalTests/Entity/DeleteMultipleFormTest.php
index 45f88d680e..ffbec00adc 100644
--- a/core/tests/Drupal/FunctionalTests/Entity/DeleteMultipleFormTest.php
+++ b/core/tests/Drupal/FunctionalTests/Entity/DeleteMultipleFormTest.php
@@ -29,7 +29,7 @@ class DeleteMultipleFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'user', 'language'];
+  protected static $modules = ['entity_test', 'user', 'language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonAnonTest.php
index 688f26b5f4..e76976dbe3 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class BaseFieldOverrideHalJsonAnonTest extends BaseFieldOverrideResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonBasicAuthTest.php
index 84907fcc57..3fc7faf18c 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class BaseFieldOverrideHalJsonBasicAuthTest extends BaseFieldOverrideResourceTes
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonCookieTest.php b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonCookieTest.php
index e373bd824b..db151a7fe0 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonCookieTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/BaseFieldOverrideHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class BaseFieldOverrideHalJsonCookieTest extends BaseFieldOverrideResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonAnonTest.php
index 443b607afa..7ff4551075 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class DateFormatHalJsonAnonTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonBasicAuthTest.php
index afab361f3c..9ee71e6c4b 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class DateFormatHalJsonBasicAuthTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonCookieTest.php b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonCookieTest.php
index 2b0fbd6a2e..78e250e76d 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonCookieTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/DateFormatHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class DateFormatHalJsonCookieTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonAnonTest.php
index 1729c456bd..4876a93f86 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityFormDisplayHalJsonAnonTest extends EntityFormDisplayResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonBasicAuthTest.php
index c8adf75796..e25367a1c2 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EntityFormDisplayHalJsonBasicAuthTest extends EntityFormDisplayResourceTes
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonCookieTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonCookieTest.php
index d519e4a8df..1be4703fa8 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonCookieTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormDisplayHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityFormDisplayHalJsonCookieTest extends EntityFormDisplayResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonAnonTest.php
index 85d3b6f116..d776889425 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityFormModeHalJsonAnonTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonBasicAuthTest.php
index 373a13eb66..9f8f576425 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EntityFormModeHalJsonBasicAuthTest extends EntityFormModeResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonCookieTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonCookieTest.php
index 2df80e31c2..035980a0fb 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonCookieTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityFormModeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityFormModeHalJsonCookieTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonAnonTest.php
index ff5feaef5e..0c2c54ba7c 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityViewDisplayHalJsonAnonTest extends EntityViewDisplayResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonBasicAuthTest.php
index 4ba2f44465..21def834e1 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityViewDisplayHalJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityViewDisplayHalJsonBasicAuthTest extends EntityViewDisplayHalJsonAnon
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonAnonTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonAnonTest.php
index fdd5d7c46c..e97411eba6 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonAnonTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityViewModeHalJsonAnonTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonBasicAuthTest.php
index e13ea25b03..b88364e5d1 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonBasicAuthTest.php
@@ -15,7 +15,7 @@ class EntityViewModeHalJsonBasicAuthTest extends EntityViewModeResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal', 'basic_auth'];
+  protected static $modules = ['hal', 'basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonCookieTest.php b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonCookieTest.php
index b5f4ad470f..db9a9180e8 100644
--- a/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonCookieTest.php
+++ b/core/tests/Drupal/FunctionalTests/Hal/EntityViewModeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityViewModeHalJsonCookieTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/HttpKernel/CorsIntegrationTest.php b/core/tests/Drupal/FunctionalTests/HttpKernel/CorsIntegrationTest.php
index cc43936d6f..b803769193 100644
--- a/core/tests/Drupal/FunctionalTests/HttpKernel/CorsIntegrationTest.php
+++ b/core/tests/Drupal/FunctionalTests/HttpKernel/CorsIntegrationTest.php
@@ -19,7 +19,7 @@ class CorsIntegrationTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'test_page_test', 'page_cache'];
+  protected static $modules = ['system', 'test_page_test', 'page_cache'];
 
   public function testCrossSiteRequest() {
     // Test default parameters.
diff --git a/core/tests/Drupal/FunctionalTests/Image/ToolkitSetupFormTest.php b/core/tests/Drupal/FunctionalTests/Image/ToolkitSetupFormTest.php
index d501f1d98c..eecf9e4e92 100644
--- a/core/tests/Drupal/FunctionalTests/Image/ToolkitSetupFormTest.php
+++ b/core/tests/Drupal/FunctionalTests/Image/ToolkitSetupFormTest.php
@@ -23,7 +23,7 @@ class ToolkitSetupFormTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'image_test'];
+  protected static $modules = ['system', 'image_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Image/ToolkitTestBase.php b/core/tests/Drupal/FunctionalTests/Image/ToolkitTestBase.php
index 4e2f5decbe..7dc0abe969 100644
--- a/core/tests/Drupal/FunctionalTests/Image/ToolkitTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Image/ToolkitTestBase.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = ['image_test'];
+  protected static $modules = ['image_test'];
 
   /**
    * The URI for the file.
diff --git a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideJsonBasicAuthTest.php
index c40de5517b..c068675a70 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class BaseFieldOverrideJsonBasicAuthTest extends BaseFieldOverrideResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideResourceTestBase.php
index 2c909807a7..801c058482 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'node'];
+  protected static $modules = ['field', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideXmlBasicAuthTest.php
index 1e3f833567..57915bd5c3 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/BaseFieldOverrideXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class BaseFieldOverrideXmlBasicAuthTest extends BaseFieldOverrideResourceTestBas
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/DateFormatJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/DateFormatJsonBasicAuthTest.php
index 453f8a1920..f96c237146 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/DateFormatJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/DateFormatJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class DateFormatJsonBasicAuthTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/DateFormatResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/DateFormatResourceTestBase.php
index 30cc347e5d..aea62d4d17 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/DateFormatResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/DateFormatResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/DateFormatXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/DateFormatXmlBasicAuthTest.php
index eb787a99b8..a844d21d73 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/DateFormatXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/DateFormatXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class DateFormatXmlBasicAuthTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayJsonBasicAuthTest.php
index 36ca913edd..fe9a789820 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityFormDisplayJsonBasicAuthTest extends EntityFormDisplayResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayResourceTestBase.php
index a44534a31f..9b68f31a57 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayXmlBasicAuthTest.php
index 2edf2460a9..8bb0357095 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormDisplayXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityFormDisplayXmlBasicAuthTest extends EntityFormDisplayResourceTestBas
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeJsonBasicAuthTest.php
index bbfb6fbc98..0f5dc63146 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityFormModeJsonBasicAuthTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeResourceTestBase.php
index e03710ab41..362006ed1b 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeResourceTestBase.php
@@ -12,7 +12,7 @@
    *
    * @todo: Remove 'field_ui' when https://www.drupal.org/node/2867266.
    */
-  public static $modules = ['user', 'field_ui'];
+  protected static $modules = ['user', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeXmlBasicAuthTest.php
index 721ded8fd9..2888632aa0 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityFormModeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityFormModeXmlBasicAuthTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayJsonBasicAuthTest.php
index f4f2d15045..8e5901529a 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityViewDisplayJsonBasicAuthTest extends EntityViewDisplayResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayResourceTestBase.php
index 7ca5f81a55..2f0428578a 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayXmlBasicAuthTest.php
index 7c7ce5bb03..531e4c9cfc 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewDisplayXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityViewDisplayXmlBasicAuthTest extends EntityViewDisplayResourceTestBas
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeJsonBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeJsonBasicAuthTest.php
index e34a58c660..cb4337ce23 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeJsonBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeJsonBasicAuthTest.php
@@ -14,7 +14,7 @@ class EntityViewModeJsonBasicAuthTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeResourceTestBase.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeResourceTestBase.php
index b20ce6368f..67b5046d52 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeResourceTestBase.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeResourceTestBase.php
@@ -12,7 +12,7 @@
    *
    * @todo: Remove 'field_ui' when https://www.drupal.org/node/2867266.
    */
-  public static $modules = ['user', 'field_ui'];
+  protected static $modules = ['user', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeXmlBasicAuthTest.php b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeXmlBasicAuthTest.php
index 1b1e7181d0..5ba7aca6f9 100644
--- a/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeXmlBasicAuthTest.php
+++ b/core/tests/Drupal/FunctionalTests/Rest/EntityViewModeXmlBasicAuthTest.php
@@ -16,7 +16,7 @@ class EntityViewModeXmlBasicAuthTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['basic_auth'];
+  protected static $modules = ['basic_auth'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Routing/CaseInsensitivePathTest.php b/core/tests/Drupal/FunctionalTests/Routing/CaseInsensitivePathTest.php
index 96b59d7be0..afb8c1e4fc 100644
--- a/core/tests/Drupal/FunctionalTests/Routing/CaseInsensitivePathTest.php
+++ b/core/tests/Drupal/FunctionalTests/Routing/CaseInsensitivePathTest.php
@@ -14,7 +14,7 @@ class CaseInsensitivePathTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'views', 'node', 'system_test'];
+  protected static $modules = ['system', 'views', 'node', 'system_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/FunctionalTests/Routing/DefaultFormatTest.php b/core/tests/Drupal/FunctionalTests/Routing/DefaultFormatTest.php
index bf695d658b..e7e4095b76 100644
--- a/core/tests/Drupal/FunctionalTests/Routing/DefaultFormatTest.php
+++ b/core/tests/Drupal/FunctionalTests/Routing/DefaultFormatTest.php
@@ -12,7 +12,7 @@ class DefaultFormatTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'default_format_test'];
+  protected static $modules = ['system', 'default_format_test'];
 
   public function testFoo() {
     $this->drupalGet('/default_format_test/human');
diff --git a/core/tests/Drupal/FunctionalTests/Routing/PathEncodedTest.php b/core/tests/Drupal/FunctionalTests/Routing/PathEncodedTest.php
index a8aee89711..8332399067 100644
--- a/core/tests/Drupal/FunctionalTests/Routing/PathEncodedTest.php
+++ b/core/tests/Drupal/FunctionalTests/Routing/PathEncodedTest.php
@@ -15,7 +15,7 @@ class PathEncodedTest extends BrowserTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'path_encoded_test'];
+  protected static $modules = ['system', 'path_encoded_test'];
 
   public function testGetEncoded() {
     $route_paths = [
diff --git a/core/tests/Drupal/FunctionalTests/Routing/RouteCachingLanguageTest.php b/core/tests/Drupal/FunctionalTests/Routing/RouteCachingLanguageTest.php
index f82cbb425a..0fd459a255 100644
--- a/core/tests/Drupal/FunctionalTests/Routing/RouteCachingLanguageTest.php
+++ b/core/tests/Drupal/FunctionalTests/Routing/RouteCachingLanguageTest.php
@@ -20,7 +20,7 @@ class RouteCachingLanguageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['path', 'node', 'content_translation', 'link', 'block'];
+  protected static $modules = ['path', 'node', 'content_translation', 'link', 'block'];
 
   /**
    * An user with permissions to administer content types.
diff --git a/core/tests/Drupal/FunctionalTests/Routing/RouteCachingNonPathLanguageNegotiationTest.php b/core/tests/Drupal/FunctionalTests/Routing/RouteCachingNonPathLanguageNegotiationTest.php
index 07286121b3..8907ab2444 100644
--- a/core/tests/Drupal/FunctionalTests/Routing/RouteCachingNonPathLanguageNegotiationTest.php
+++ b/core/tests/Drupal/FunctionalTests/Routing/RouteCachingNonPathLanguageNegotiationTest.php
@@ -18,7 +18,7 @@ class RouteCachingNonPathLanguageNegotiationTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'block'];
+  protected static $modules = ['language', 'block'];
 
   /**
    * The admin user.
diff --git a/core/tests/Drupal/KernelTests/Component/Utility/SafeMarkupKernelTest.php b/core/tests/Drupal/KernelTests/Component/Utility/SafeMarkupKernelTest.php
index 3028b62dd0..468a235c50 100644
--- a/core/tests/Drupal/KernelTests/Component/Utility/SafeMarkupKernelTest.php
+++ b/core/tests/Drupal/KernelTests/Component/Utility/SafeMarkupKernelTest.php
@@ -16,7 +16,7 @@ class SafeMarkupKernelTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php b/core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php
index 39a5accae3..63777157f3 100644
--- a/core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php
+++ b/core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php
@@ -27,7 +27,7 @@ class DefaultConfigTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * The following config entries are changed on module install.
diff --git a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
index bc9c441d51..674a8bbed6 100644
--- a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
+++ b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
@@ -21,7 +21,7 @@ class TypedConfigTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Action/DeleteActionTest.php b/core/tests/Drupal/KernelTests/Core/Action/DeleteActionTest.php
index e5a2bd95da..1c2c13deee 100644
--- a/core/tests/Drupal/KernelTests/Core/Action/DeleteActionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Action/DeleteActionTest.php
@@ -18,7 +18,7 @@ class DeleteActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'entity_test', 'user'];
+  protected static $modules = ['system', 'entity_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Action/PublishActionTest.php b/core/tests/Drupal/KernelTests/Core/Action/PublishActionTest.php
index d381de115d..384597eb28 100644
--- a/core/tests/Drupal/KernelTests/Core/Action/PublishActionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Action/PublishActionTest.php
@@ -15,7 +15,7 @@ class PublishActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'entity_test', 'user'];
+  protected static $modules = ['system', 'entity_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Action/SaveActionTest.php b/core/tests/Drupal/KernelTests/Core/Action/SaveActionTest.php
index ed9b2873a3..bf63a770b9 100644
--- a/core/tests/Drupal/KernelTests/Core/Action/SaveActionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Action/SaveActionTest.php
@@ -15,7 +15,7 @@ class SaveActionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'entity_test', 'user'];
+  protected static $modules = ['system', 'entity_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
index fff73c2986..7279a1553c 100644
--- a/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
@@ -38,7 +38,7 @@ class AttachedAssetsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'simpletest', 'common_test', 'system'];
+  protected static $modules = ['language', 'simpletest', 'common_test', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Asset/ResolvedLibraryDefinitionsFilesMatchTest.php b/core/tests/Drupal/KernelTests/Core/Asset/ResolvedLibraryDefinitionsFilesMatchTest.php
index bbb3d6a5a0..3fc5cc65d7 100644
--- a/core/tests/Drupal/KernelTests/Core/Asset/ResolvedLibraryDefinitionsFilesMatchTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Asset/ResolvedLibraryDefinitionsFilesMatchTest.php
@@ -86,7 +86,7 @@ class ResolvedLibraryDefinitionsFilesMatchTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Block/MultipleBlockFormTest.php b/core/tests/Drupal/KernelTests/Core/Block/MultipleBlockFormTest.php
index 2fbe025acf..140621fc03 100644
--- a/core/tests/Drupal/KernelTests/Core/Block/MultipleBlockFormTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Block/MultipleBlockFormTest.php
@@ -15,7 +15,7 @@ class MultipleBlockFormTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'block', 'block_test'];
+  protected static $modules = ['system', 'block', 'block_test'];
 
   /**
    * Tests that blocks can have multiple forms.
diff --git a/core/tests/Drupal/KernelTests/Core/Bootstrap/GetFilenameTest.php b/core/tests/Drupal/KernelTests/Core/Bootstrap/GetFilenameTest.php
index 396facf158..74e418110c 100644
--- a/core/tests/Drupal/KernelTests/Core/Bootstrap/GetFilenameTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Bootstrap/GetFilenameTest.php
@@ -15,7 +15,7 @@ class GetFilenameTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Cache/CacheContextOptimizationTest.php b/core/tests/Drupal/KernelTests/Core/Cache/CacheContextOptimizationTest.php
index 0ae0230535..6cfce9e599 100644
--- a/core/tests/Drupal/KernelTests/Core/Cache/CacheContextOptimizationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Cache/CacheContextOptimizationTest.php
@@ -20,7 +20,7 @@ class CacheContextOptimizationTest extends KernelTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTagTest.php b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTagTest.php
index 0fefc390f4..99f14dd1d1 100644
--- a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTagTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTagTest.php
@@ -19,7 +19,7 @@ class DatabaseBackendTagTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
index 358b92530c..4563bfe2d8 100644
--- a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
@@ -23,7 +23,7 @@ class DatabaseBackendTest extends GenericCacheBackendUnitTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Creates a new instance of DatabaseBackend.
diff --git a/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php b/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
index 16070c0e2e..7b06347892 100644
--- a/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
@@ -22,7 +22,7 @@ class DbDumpTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'config', 'dblog', 'menu_link_content', 'link', 'block_content', 'file', 'user'];
+  protected static $modules = ['system', 'config', 'dblog', 'menu_link_content', 'link', 'block_content', 'file', 'user'];
 
   /**
    * Test data to write into config.
diff --git a/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php b/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
index 23754879eb..f2a7c10397 100644
--- a/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Common/XssUnitTest.php
@@ -18,7 +18,7 @@ class XssUnitTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'system'];
+  protected static $modules = ['filter', 'system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/CacheabilityMetadataConfigOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Config/CacheabilityMetadataConfigOverrideTest.php
index 4ceebf5b9b..55eabda6f5 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/CacheabilityMetadataConfigOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/CacheabilityMetadataConfigOverrideTest.php
@@ -15,7 +15,7 @@ class CacheabilityMetadataConfigOverrideTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'block_content',
     'config',
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigCRUDTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigCRUDTest.php
index 99a94d182f..49d8921ba2 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigCRUDTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigCRUDTest.php
@@ -32,7 +32,7 @@ class ConfigCRUDTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests CRUD operations.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigDependencyTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigDependencyTest.php
index 6a0f938bd4..7ed0912033 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigDependencyTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigDependencyTest.php
@@ -21,7 +21,7 @@ class ConfigDependencyTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'entity_test', 'user'];
+  protected static $modules = ['config_test', 'entity_test', 'user'];
 
   /**
    * Tests that calculating dependencies for system module.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigDiffTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigDiffTest.php
index f29b88acd1..2798176715 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigDiffTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigDiffTest.php
@@ -16,7 +16,7 @@ class ConfigDiffTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'system'];
+  protected static $modules = ['config_test', 'system'];
 
   /**
    * Tests calculating the difference between two sets of configuration.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityNormalizeTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityNormalizeTest.php
index 1b468b0670..7775f808fa 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityNormalizeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityNormalizeTest.php
@@ -16,7 +16,7 @@ class ConfigEntityNormalizeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStaticCacheTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStaticCacheTest.php
index 1cd9cb1753..71d7d9c909 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStaticCacheTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStaticCacheTest.php
@@ -17,7 +17,7 @@ class ConfigEntityStaticCacheTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'config_entity_static_cache_test'];
+  protected static $modules = ['config_test', 'config_entity_static_cache_test'];
 
   /**
    * The type ID of the entity under test.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStatusTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStatusTest.php
index 20ceef4051..de48a32422 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStatusTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStatusTest.php
@@ -16,7 +16,7 @@ class ConfigEntityStatusTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests the enabling/disabling of entities.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
index ce9a928d53..104ae7a045 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityStorageTest.php
@@ -18,7 +18,7 @@ class ConfigEntityStorageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Tests creating configuration entities with changed UUIDs.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityUnitTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityUnitTest.php
index 154d2383b4..60c8361f0b 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityUnitTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEntityUnitTest.php
@@ -25,7 +25,7 @@ class ConfigEntityUnitTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * The config_test entity storage.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigEventsTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigEventsTest.php
index 74bb7984e6..851fd6a8c0 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigEventsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigEventsTest.php
@@ -18,7 +18,7 @@ class ConfigEventsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_events_test'];
+  protected static $modules = ['config_events_test'];
 
   /**
    * Tests configuration events.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php
index fef464ed7f..dedfbe9073 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php
@@ -26,7 +26,7 @@ class ConfigImportRecreateTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'field', 'text', 'user', 'node'];
+  protected static $modules = ['system', 'field', 'text', 'user', 'node'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
index f52b3956ab..06648b0004 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
@@ -29,7 +29,7 @@ class ConfigImportRenameValidationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'node', 'field', 'text', 'config_test'];
+  protected static $modules = ['system', 'user', 'node', 'field', 'text', 'config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterMissingContentTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterMissingContentTest.php
index db09e3f9f6..036d7521fb 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterMissingContentTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterMissingContentTest.php
@@ -26,7 +26,7 @@ class ConfigImporterMissingContentTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'entity_test', 'config_test', 'config_import_test'];
+  protected static $modules = ['system', 'user', 'entity_test', 'config_test', 'config_import_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
index 41795e8c87..c4e797b335 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
@@ -33,7 +33,7 @@ class ConfigImporterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'system', 'config_import_test'];
+  protected static $modules = ['config_test', 'system', 'config_import_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigInstallTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigInstallTest.php
index 5efd20bbb1..4bfed9ab67 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigInstallTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigInstallTest.php
@@ -18,7 +18,7 @@ class ConfigInstallTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigLanguageOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigLanguageOverrideTest.php
index 5bf6f0ec47..e249bd37d8 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigLanguageOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigLanguageOverrideTest.php
@@ -17,7 +17,7 @@ class ConfigLanguageOverrideTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'language', 'config_test', 'system', 'field'];
+  protected static $modules = ['user', 'language', 'config_test', 'system', 'field'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigModuleOverridesTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigModuleOverridesTest.php
index a94123d4cb..d88ab6ade1 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigModuleOverridesTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigModuleOverridesTest.php
@@ -16,7 +16,7 @@ class ConfigModuleOverridesTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'config', 'config_override_test'];
+  protected static $modules = ['system', 'config', 'config_override_test'];
 
   public function testSimpleModuleOverrides() {
     $GLOBALS['config_test_run_module_overrides'] = TRUE;
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverrideTest.php
index 550e0d5b2b..bbf690e40a 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverrideTest.php
@@ -16,7 +16,7 @@ class ConfigOverrideTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'config_test'];
+  protected static $modules = ['system', 'config_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
index 6c568b8417..67c280c277 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigOverridesPriorityTest.php
@@ -18,7 +18,7 @@ class ConfigOverridesPriorityTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'config', 'config_override_test', 'language'];
+  protected static $modules = ['system', 'config', 'config_override_test', 'language'];
 
   public function testOverridePriorities() {
     $GLOBALS['config_test_run_module_overrides'] = FALSE;
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigSchemaTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigSchemaTest.php
index e16225d0ec..00b93711bf 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigSchemaTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigSchemaTest.php
@@ -25,7 +25,7 @@ class ConfigSchemaTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'language', 'field', 'image', 'config_test', 'config_schema_test'];
+  protected static $modules = ['system', 'language', 'field', 'image', 'config_test', 'config_schema_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/ConfigSnapshotTest.php b/core/tests/Drupal/KernelTests/Core/Config/ConfigSnapshotTest.php
index 645638d832..73766d5f51 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigSnapshotTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigSnapshotTest.php
@@ -17,7 +17,7 @@ class ConfigSnapshotTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'system'];
+  protected static $modules = ['config_test', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/DefaultConfigTest.php b/core/tests/Drupal/KernelTests/Core/Config/DefaultConfigTest.php
index f06806cad6..082237da5d 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/DefaultConfigTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/DefaultConfigTest.php
@@ -23,7 +23,7 @@ class DefaultConfigTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'config_test'];
+  protected static $modules = ['system', 'config_test'];
 
   /**
    * Themes which provide default configuration and need enabling.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/Entity/ConfigEntityUpdaterTest.php b/core/tests/Drupal/KernelTests/Core/Config/Entity/ConfigEntityUpdaterTest.php
index 5aae17f7d6..d37cfa6c23 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/Entity/ConfigEntityUpdaterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/Entity/ConfigEntityUpdaterTest.php
@@ -19,7 +19,7 @@ class ConfigEntityUpdaterTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * @covers ::update
diff --git a/core/tests/Drupal/KernelTests/Core/Config/SchemaCheckTraitTest.php b/core/tests/Drupal/KernelTests/Core/Config/SchemaCheckTraitTest.php
index a11bcb6592..2a879d7161 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/SchemaCheckTraitTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/SchemaCheckTraitTest.php
@@ -26,7 +26,7 @@ class SchemaCheckTraitTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test', 'config_schema_test'];
+  protected static $modules = ['config_test', 'config_schema_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Config/SchemaConfigListenerTest.php b/core/tests/Drupal/KernelTests/Core/Config/SchemaConfigListenerTest.php
index 2674a3c6df..4518b727de 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/SchemaConfigListenerTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/SchemaConfigListenerTest.php
@@ -17,7 +17,7 @@ class SchemaConfigListenerTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php b/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php
index d044e3df38..2dd2e5de8c 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php
@@ -18,7 +18,7 @@ class DatabaseLegacyTest extends DatabaseTestBase {
    *
    * @var array
    */
-  public static $modules = ['database_test', 'system'];
+  protected static $modules = ['database_test', 'system'];
 
   /**
    * Tests deprecation of the db_and() function.
diff --git a/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php b/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
index 784bfd6189..fca5fa3305 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
@@ -13,7 +13,7 @@
  */
 abstract class DatabaseTestBase extends KernelTestBase {
 
-  public static $modules = ['database_test'];
+  protected static $modules = ['database_test'];
 
   /**
    * The database connection for testing.
diff --git a/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php b/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
index 9adb214b92..5f2e1afb9c 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
@@ -14,7 +14,7 @@ class NextIdTest extends DatabaseTestBase {
    *
    * @var array
    */
-  public static $modules = ['database_test', 'system'];
+  protected static $modules = ['database_test', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
index 4dee52d5c7..0cd44d7380 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
@@ -14,7 +14,7 @@ class RegressionTest extends DatabaseTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * Ensures that non-ASCII UTF-8 data is stored in the database properly.
diff --git a/core/tests/Drupal/KernelTests/Core/Database/SelectComplexTest.php b/core/tests/Drupal/KernelTests/Core/Database/SelectComplexTest.php
index 23ec66494a..42f5a5ff86 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/SelectComplexTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/SelectComplexTest.php
@@ -19,7 +19,7 @@ class SelectComplexTest extends DatabaseTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'node_access_test', 'field'];
+  protected static $modules = ['system', 'user', 'node_access_test', 'field'];
 
   /**
    * Tests simple JOIN statements.
diff --git a/core/tests/Drupal/KernelTests/Core/Datetime/FormatDateTest.php b/core/tests/Drupal/KernelTests/Core/Datetime/FormatDateTest.php
index 036b385ae4..a127447bfd 100644
--- a/core/tests/Drupal/KernelTests/Core/Datetime/FormatDateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Datetime/FormatDateTest.php
@@ -15,7 +15,7 @@ class FormatDateTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'system'];
+  protected static $modules = ['language', 'system'];
 
   /**
    * Arbitrary langcode for a custom language.
diff --git a/core/tests/Drupal/KernelTests/Core/Element/PathElementFormTest.php b/core/tests/Drupal/KernelTests/Core/Element/PathElementFormTest.php
index b5b9ffd5ec..12aa7ef304 100644
--- a/core/tests/Drupal/KernelTests/Core/Element/PathElementFormTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Element/PathElementFormTest.php
@@ -30,7 +30,7 @@ class PathElementFormTest extends KernelTestBase implements FormInterface {
    *
    * @var array
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * Sets up the test.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/BundleConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/BundleConstraintValidatorTest.php
index 613ba4e17d..5af2c6d428 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/BundleConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/BundleConstraintValidatorTest.php
@@ -19,7 +19,7 @@ class BundleConstraintValidatorTest extends KernelTestBase {
    */
   protected $typedData;
 
-  public static $modules = ['node', 'field', 'text', 'user'];
+  protected static $modules = ['node', 'field', 'text', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityAdapterTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityAdapterTest.php
index af9403c320..45443c9c35 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityAdapterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityAdapterTest.php
@@ -23,7 +23,7 @@ class ConfigEntityAdapterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * The config entity.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php
index 839917aff0..5af84ff339 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php
@@ -19,7 +19,7 @@ class ConfigEntityQueryTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * Stores the search results for alter comparison.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
index aa0044bd8e..d165e7016a 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityChangedTest.php
@@ -18,7 +18,7 @@ class ContentEntityChangedTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'user', 'system', 'field', 'text', 'filter', 'entity_test'];
+  protected static $modules = ['language', 'user', 'system', 'field', 'text', 'filter', 'entity_test'];
 
   /**
    * The EntityTestMulChanged entity type storage.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityCloneTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityCloneTest.php
index 8f08b272de..edce7660cd 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityCloneTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityCloneTest.php
@@ -17,7 +17,7 @@ class ContentEntityCloneTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'entity_test'];
+  protected static $modules = ['language', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityFieldMethodInvocationOrderTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityFieldMethodInvocationOrderTest.php
index 5e25c90e0a..dda9da27e6 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityFieldMethodInvocationOrderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityFieldMethodInvocationOrderTest.php
@@ -16,7 +16,7 @@ class ContentEntityFieldMethodInvocationOrderTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language', 'system', 'entity_test'];
+  protected static $modules = ['language', 'system', 'entity_test'];
 
   /**
    * The EntityTest entity type storage.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityHasChangesTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityHasChangesTest.php
index 687ceb74c0..39ec64dcc4 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityHasChangesTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityHasChangesTest.php
@@ -22,7 +22,7 @@ class ContentEntityHasChangesTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'entity_test'];
+  protected static $modules = ['system', 'user', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNonRevisionableFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNonRevisionableFieldTest.php
index 99c99b0688..8c82ce5625 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNonRevisionableFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNonRevisionableFieldTest.php
@@ -18,7 +18,7 @@ class ContentEntityNonRevisionableFieldTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * The EntityTestMulRev entity type storage.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNullStorageTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNullStorageTest.php
index 001d9ba3de..e5a183ad8b 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNullStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNullStorageTest.php
@@ -22,7 +22,7 @@ class ContentEntityNullStorageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'contact', 'user'];
+  protected static $modules = ['system', 'contact', 'user'];
 
   /**
    * Tests using entity query with ContentEntityNullStorage.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/CreateSampleEntityTest.php b/core/tests/Drupal/KernelTests/Core/Entity/CreateSampleEntityTest.php
index b5bcd487f2..5efe4ebb95 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/CreateSampleEntityTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/CreateSampleEntityTest.php
@@ -25,7 +25,7 @@ class CreateSampleEntityTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'field', 'filter', 'text', 'file', 'user', 'node', 'comment', 'taxonomy'];
+  protected static $modules = ['system', 'field', 'filter', 'text', 'file', 'user', 'node', 'comment', 'taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/DefaultTableMappingIntegrationTest.php b/core/tests/Drupal/KernelTests/Core/Entity/DefaultTableMappingIntegrationTest.php
index 3013d2a933..2e714ee516 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/DefaultTableMappingIntegrationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/DefaultTableMappingIntegrationTest.php
@@ -26,7 +26,7 @@ class DefaultTableMappingIntegrationTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test_extra'];
+  protected static $modules = ['entity_test_extra'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityBundleFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityBundleFieldTest.php
index 22476d760a..e10d34f1b2 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityBundleFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityBundleFieldTest.php
@@ -14,7 +14,7 @@ class EntityBundleFieldTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_schema_test'];
+  protected static $modules = ['entity_schema_test'];
 
   /**
    * The module handler.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
index 16fd8c5797..b37e1f9a2a 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityCrudHookTest.php
@@ -40,7 +40,7 @@ class EntityCrudHookTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'block_test', 'entity_crud_hook_test', 'file', 'taxonomy', 'node', 'comment'];
+  protected static $modules = ['block', 'block_test', 'entity_crud_hook_test', 'file', 'taxonomy', 'node', 'comment'];
 
   protected $ids = [];
 
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
index d4fbcfcb20..40f2ecd8dd 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDecoupledTranslationRevisionsTest.php
@@ -22,7 +22,7 @@ class EntityDecoupledTranslationRevisionsTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'entity_test',
     'language',
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
index 1a743eceeb..56bf124f60 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
@@ -47,7 +47,7 @@ class EntityDefinitionUpdateTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test_update'];
+  protected static $modules = ['entity_test_update'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayBaseTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayBaseTest.php
index ec1a55cbbe..823ebb4cd5 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayBaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayBaseTest.php
@@ -18,7 +18,7 @@ class EntityDisplayBaseTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'entity_test_third_party', 'field', 'system', 'comment'];
+  protected static $modules = ['entity_test', 'entity_test_third_party', 'field', 'system', 'comment'];
 
   /**
    * @covers ::preSave
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayFormBaseTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayFormBaseTest.php
index 179c63e9f1..6f34e5ddc4 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayFormBaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDisplayFormBaseTest.php
@@ -17,7 +17,7 @@ class EntityDisplayFormBaseTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * @covers ::copyFormValuesToEntity
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php
index 3fd17d86b4..e9891de323 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php
@@ -33,7 +33,7 @@ class EntityFieldTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'text', 'node', 'user', 'field_test'];
+  protected static $modules = ['filter', 'text', 'node', 'user', 'field_test'];
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityHasFieldConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityHasFieldConstraintValidatorTest.php
index eebc94f523..ba5f604dcf 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityHasFieldConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityHasFieldConstraintValidatorTest.php
@@ -15,7 +15,7 @@ class EntityHasFieldConstraintValidatorTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test_constraints'];
+  protected static $modules = ['entity_test_constraints'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityKernelTestBase.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityKernelTestBase.php
index f7108d53b1..71fba5dcb3 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityKernelTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityKernelTestBase.php
@@ -17,7 +17,7 @@
    *
    * @var array
    */
-  public static $modules = ['user', 'system', 'field', 'text', 'filter', 'entity_test'];
+  protected static $modules = ['user', 'system', 'field', 'text', 'filter', 'entity_test'];
 
   /**
    * The entity manager service.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php
index d76c3c17f8..36ab8d3e7a 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php
@@ -39,7 +39,7 @@
    */
   protected $untranslatableFieldName;
 
-  public static $modules = ['language', 'entity_test'];
+  protected static $modules = ['language', 'entity_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php
index 2160da96e5..bf0f590333 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php
@@ -15,7 +15,7 @@ class EntityNonRevisionableTranslatableFieldTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'language', 'content_translation'];
+  protected static $modules = ['entity_test', 'language', 'content_translation'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryAggregateTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryAggregateTest.php
index 9e8de36173..09ca3d69ff 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryAggregateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryAggregateTest.php
@@ -18,7 +18,7 @@ class EntityQueryAggregateTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * The entity_test storage to create the test entities.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php
index 4e1f9d1e5d..39fcf1fd3e 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php
@@ -22,7 +22,7 @@ class EntityQueryRelationshipTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * Term entities.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
index a47d9a9a6f..a8cb8db88e 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
@@ -26,7 +26,7 @@ class EntityQueryTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field_test', 'language'];
+  protected static $modules = ['field_test', 'language'];
 
   /**
    * @var array
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php
index 469f4a32a5..aa1786048e 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceFieldTest.php
@@ -59,7 +59,7 @@ class EntityReferenceFieldTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_reference_test', 'entity_test_update'];
+  protected static $modules = ['entity_reference_test', 'entity_test_update'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
index b2c72b99d9..55e0210e9c 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityReferenceSelection/EntityReferenceSelectionSortTest.php
@@ -21,7 +21,7 @@ class EntityReferenceSelectionSortTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php
index 34969ebd4d..875adcff61 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php
@@ -16,7 +16,7 @@ class EntityRevisionTranslationTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionsTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionsTest.php
index e5407fcc96..cfec67525a 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionsTest.php
@@ -19,7 +19,7 @@ class EntityRevisionsTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'entity_test',
     'language',
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php
index 3671d6d408..201ffa6063 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php
@@ -18,7 +18,7 @@ class EntityTypeConstraintValidatorTest extends EntityKernelTestBase {
    */
   protected $typedData;
 
-  public static $modules = ['node', 'field', 'user'];
+  protected static $modules = ['node', 'field', 'user'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
index d0c01bccb5..46a634e0d5 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
@@ -35,7 +35,7 @@ class EntityTypedDataDefinitionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'filter', 'text', 'node', 'user'];
+  protected static $modules = ['system', 'filter', 'text', 'node', 'user'];
 
   protected function setUp() {
     parent::setup();
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php
index 2a6dfed6c2..c0c0d4f192 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php
@@ -17,7 +17,7 @@ class EntityValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'text', 'language'];
+  protected static $modules = ['filter', 'text', 'language'];
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
index 16f63db8d8..b775beddcc 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
@@ -22,7 +22,7 @@ class FieldSqlStorageTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'field_test', 'text', 'entity_test'];
+  protected static $modules = ['field', 'field_test', 'text', 'entity_test'];
 
   /**
    * The name of the created field.
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/FieldWidgetConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/FieldWidgetConstraintValidatorTest.php
index d3d5e5b1d4..b388585cc8 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/FieldWidgetConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/FieldWidgetConstraintValidatorTest.php
@@ -15,7 +15,7 @@
  */
 class FieldWidgetConstraintValidatorTest extends KernelTestBase {
 
-  public static $modules = ['entity_test', 'field', 'field_test', 'user', 'system'];
+  protected static $modules = ['entity_test', 'field', 'field_test', 'user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
index 74b2d6e4d8..d1ebf4b79d 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
@@ -17,7 +17,7 @@ class RevisionableContentEntityBaseTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test_revlog', 'system', 'user'];
+  protected static $modules = ['entity_test_revlog', 'system', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/RouteProviderTest.php b/core/tests/Drupal/KernelTests/Core/Entity/RouteProviderTest.php
index d68a1f5ac8..ad3608b860 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/RouteProviderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/RouteProviderTest.php
@@ -20,7 +20,7 @@ class RouteProviderTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'user', 'system'];
+  protected static $modules = ['entity_test', 'user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/ValidReferenceConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ValidReferenceConstraintValidatorTest.php
index be609d8d71..f8b4ab34b3 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/ValidReferenceConstraintValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ValidReferenceConstraintValidatorTest.php
@@ -33,7 +33,7 @@ class ValidReferenceConstraintValidatorTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'node', 'user'];
+  protected static $modules = ['field', 'node', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Extension/ModuleConfigureRouteTest.php b/core/tests/Drupal/KernelTests/Core/Extension/ModuleConfigureRouteTest.php
index 96e469a84b..cfb9e0a0be 100644
--- a/core/tests/Drupal/KernelTests/Core/Extension/ModuleConfigureRouteTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Extension/ModuleConfigureRouteTest.php
@@ -17,7 +17,7 @@ class ModuleConfigureRouteTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * @var \Drupal\Core\Routing\RouteProviderInterface
diff --git a/core/tests/Drupal/KernelTests/Core/Extension/ModuleImplementsAlterTest.php b/core/tests/Drupal/KernelTests/Core/Extension/ModuleImplementsAlterTest.php
index 7d29a26124..7eb3a3c642 100644
--- a/core/tests/Drupal/KernelTests/Core/Extension/ModuleImplementsAlterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Extension/ModuleImplementsAlterTest.php
@@ -14,7 +14,7 @@ class ModuleImplementsAlterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests hook_module_implements_alter() adding an implementation.
diff --git a/core/tests/Drupal/KernelTests/Core/Extension/ModuleInstallerTest.php b/core/tests/Drupal/KernelTests/Core/Extension/ModuleInstallerTest.php
index 7ffe65c9fc..0786f2104a 100644
--- a/core/tests/Drupal/KernelTests/Core/Extension/ModuleInstallerTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Extension/ModuleInstallerTest.php
@@ -22,7 +22,7 @@ class ModuleInstallerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests that routes are rebuilt during install and uninstall of modules.
diff --git a/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php
index 6430cb1b8b..798cfc14d7 100644
--- a/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php
@@ -19,7 +19,7 @@ class BaseFieldOverrideTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'user',
     'entity_test',
diff --git a/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php b/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php
index f273029bf2..ca7a66b212 100644
--- a/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php
@@ -19,7 +19,7 @@ class FieldAccessTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'field', 'system', 'text', 'filter', 'user'];
+  protected static $modules = ['entity_test', 'field', 'system', 'text', 'filter', 'user'];
 
   /**
    * Holds the currently active global user ID that initiated the test run.
diff --git a/core/tests/Drupal/KernelTests/Core/Field/FieldSettingsTest.php b/core/tests/Drupal/KernelTests/Core/Field/FieldSettingsTest.php
index 9229a60b0b..51ee2f8251 100644
--- a/core/tests/Drupal/KernelTests/Core/Field/FieldSettingsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Field/FieldSettingsTest.php
@@ -19,7 +19,7 @@ class FieldSettingsTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'field_test'];
+  protected static $modules = ['field', 'field_test'];
 
   /**
    * @covers \Drupal\Core\Field\BaseFieldDefinition::getSettings
diff --git a/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php b/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
index 92612ae7fd..c5b7477ad8 100644
--- a/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/File/FileTestBase.php
@@ -16,7 +16,7 @@
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/MimeTypeTest.php b/core/tests/Drupal/KernelTests/Core/File/MimeTypeTest.php
index 4eca9976f2..918e568b05 100644
--- a/core/tests/Drupal/KernelTests/Core/File/MimeTypeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/MimeTypeTest.php
@@ -14,7 +14,7 @@ class MimeTypeTest extends FileTestBase {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * Test mapping of mimetypes from filenames.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileDirectoryTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileDirectoryTest.php
index e41fb74e2e..69a1a11880 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileDirectoryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileDirectoryTest.php
@@ -14,7 +14,7 @@ class RemoteFileDirectoryTest extends DirectoryTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileScanDirectoryTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileScanDirectoryTest.php
index e3c68a72f3..e38b04811d 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileScanDirectoryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileScanDirectoryTest.php
@@ -14,7 +14,7 @@ class RemoteFileScanDirectoryTest extends ScanDirectoryTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedCopyTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedCopyTest.php
index b13b92cba5..cf8b425d9b 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedCopyTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedCopyTest.php
@@ -14,7 +14,7 @@ class RemoteFileUnmanagedCopyTest extends UnmanagedCopyTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteRecursiveTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteRecursiveTest.php
index 6be98df4aa..dc9de903cc 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteRecursiveTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteRecursiveTest.php
@@ -14,7 +14,7 @@ class RemoteFileUnmanagedDeleteRecursiveTest extends UnmanagedDeleteRecursiveTes
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteTest.php
index f826d4dd29..91b1903d1a 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedDeleteTest.php
@@ -14,7 +14,7 @@ class RemoteFileUnmanagedDeleteTest extends UnmanagedDeleteTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedMoveTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedMoveTest.php
index e41f87e694..b8b257e283 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedMoveTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedMoveTest.php
@@ -14,7 +14,7 @@ class RemoteFileUnmanagedMoveTest extends UnmanagedMoveTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedSaveDataTest.php b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedSaveDataTest.php
index 817da28288..c5e267561b 100644
--- a/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedSaveDataTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/RemoteFileUnmanagedSaveDataTest.php
@@ -14,7 +14,7 @@ class RemoteFileUnmanagedSaveDataTest extends UnmanagedSaveDataTest {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/ScanDirectoryTest.php b/core/tests/Drupal/KernelTests/Core/File/ScanDirectoryTest.php
index a096ae8526..849a70c660 100644
--- a/core/tests/Drupal/KernelTests/Core/File/ScanDirectoryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/ScanDirectoryTest.php
@@ -14,7 +14,7 @@ class ScanDirectoryTest extends FileTestBase {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/File/StreamWrapperTest.php b/core/tests/Drupal/KernelTests/Core/File/StreamWrapperTest.php
index 6c18b6654c..ee12b81336 100644
--- a/core/tests/Drupal/KernelTests/Core/File/StreamWrapperTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/StreamWrapperTest.php
@@ -19,7 +19,7 @@ class StreamWrapperTest extends FileTestBase {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * A stream wrapper scheme to register for the test.
diff --git a/core/tests/Drupal/KernelTests/Core/File/UrlRewritingTest.php b/core/tests/Drupal/KernelTests/Core/File/UrlRewritingTest.php
index ff401e112c..6e146ca1f5 100644
--- a/core/tests/Drupal/KernelTests/Core/File/UrlRewritingTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/UrlRewritingTest.php
@@ -16,7 +16,7 @@ class UrlRewritingTest extends FileTestBase {
    *
    * @var array
    */
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * Tests the rewriting of shipped file URLs by hook_file_url_alter().
diff --git a/core/tests/Drupal/KernelTests/Core/File/UrlTransformRelativeTest.php b/core/tests/Drupal/KernelTests/Core/File/UrlTransformRelativeTest.php
index 6614b2d5b4..a7a8f3e596 100644
--- a/core/tests/Drupal/KernelTests/Core/File/UrlTransformRelativeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/File/UrlTransformRelativeTest.php
@@ -12,7 +12,7 @@
  */
 class UrlTransformRelativeTest extends KernelTestBase {
 
-  public static $modules = ['file_test'];
+  protected static $modules = ['file_test'];
 
   /**
    * Tests file_url_transform_relative function.
diff --git a/core/tests/Drupal/KernelTests/Core/Form/ExternalFormUrlTest.php b/core/tests/Drupal/KernelTests/Core/Form/ExternalFormUrlTest.php
index f3fbc4f76c..b0c8006286 100644
--- a/core/tests/Drupal/KernelTests/Core/Form/ExternalFormUrlTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Form/ExternalFormUrlTest.php
@@ -18,7 +18,7 @@ class ExternalFormUrlTest extends KernelTestBase implements FormInterface {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php b/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
index f6fb4f8713..0958392c10 100644
--- a/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Form/FormCacheTest.php
@@ -21,7 +21,7 @@ class FormCacheTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/Form/FormDefaultHandlersTest.php b/core/tests/Drupal/KernelTests/Core/Form/FormDefaultHandlersTest.php
index 6d79f17cfb..701c45f8a3 100644
--- a/core/tests/Drupal/KernelTests/Core/Form/FormDefaultHandlersTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Form/FormDefaultHandlersTest.php
@@ -19,7 +19,7 @@ class FormDefaultHandlersTest extends KernelTestBase implements FormInterface {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/HttpKernel/StackKernelIntegrationTest.php b/core/tests/Drupal/KernelTests/Core/HttpKernel/StackKernelIntegrationTest.php
index 29bbcff9a8..393ec93656 100644
--- a/core/tests/Drupal/KernelTests/Core/HttpKernel/StackKernelIntegrationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/HttpKernel/StackKernelIntegrationTest.php
@@ -19,7 +19,7 @@ class StackKernelIntegrationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['httpkernel_test', 'system'];
+  protected static $modules = ['httpkernel_test', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Image/ToolkitGdTest.php b/core/tests/Drupal/KernelTests/Core/Image/ToolkitGdTest.php
index dba742df22..d1b0b4c756 100644
--- a/core/tests/Drupal/KernelTests/Core/Image/ToolkitGdTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Image/ToolkitGdTest.php
@@ -42,7 +42,7 @@ class ToolkitGdTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'simpletest'];
+  protected static $modules = ['system', 'simpletest'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageExpirableTest.php b/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageExpirableTest.php
index 26a1abeff1..64fb0e4d37 100644
--- a/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageExpirableTest.php
+++ b/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageExpirableTest.php
@@ -17,7 +17,7 @@ class DatabaseStorageExpirableTest extends StorageTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageTest.php b/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageTest.php
index 5852da143f..9e6bd9c501 100644
--- a/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/KeyValueStore/DatabaseStorageTest.php
@@ -17,7 +17,7 @@ class DatabaseStorageTest extends StorageTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php b/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
index b021e8ab4b..f669aa226c 100644
--- a/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
@@ -19,7 +19,7 @@ class GarbageCollectionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/KeyValueStore/KeyValueContentEntityStorageTest.php b/core/tests/Drupal/KernelTests/Core/KeyValueStore/KeyValueContentEntityStorageTest.php
index 98850055a5..c49a2a2137 100644
--- a/core/tests/Drupal/KernelTests/Core/KeyValueStore/KeyValueContentEntityStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/KeyValueStore/KeyValueContentEntityStorageTest.php
@@ -19,7 +19,7 @@ class KeyValueContentEntityStorageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'entity_test', 'keyvalue_test'];
+  protected static $modules = ['user', 'entity_test', 'keyvalue_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkDefaultIntegrationTest.php b/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkDefaultIntegrationTest.php
index d0da9130a6..47fbe2bb93 100644
--- a/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkDefaultIntegrationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkDefaultIntegrationTest.php
@@ -17,7 +17,7 @@ class MenuLinkDefaultIntegrationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'menu_test',
   ];
 
diff --git a/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkTreeTest.php b/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkTreeTest.php
index 04c04aa3e3..49ed72504e 100644
--- a/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkTreeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Menu/MenuLinkTreeTest.php
@@ -35,7 +35,7 @@ class MenuLinkTreeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'menu_test',
     'menu_link_content',
diff --git a/core/tests/Drupal/KernelTests/Core/ParamConverter/EntityConverterLatestRevisionTest.php b/core/tests/Drupal/KernelTests/Core/ParamConverter/EntityConverterLatestRevisionTest.php
index 40d38867f0..bb6d2e88fd 100644
--- a/core/tests/Drupal/KernelTests/Core/ParamConverter/EntityConverterLatestRevisionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/ParamConverter/EntityConverterLatestRevisionTest.php
@@ -20,7 +20,7 @@ class EntityConverterLatestRevisionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'user',
     'language',
diff --git a/core/tests/Drupal/KernelTests/Core/Path/AliasStorageTest.php b/core/tests/Drupal/KernelTests/Core/Path/AliasStorageTest.php
index d7b24b497f..e9967f5b24 100644
--- a/core/tests/Drupal/KernelTests/Core/Path/AliasStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Path/AliasStorageTest.php
@@ -14,7 +14,7 @@ class AliasStorageTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * @var \Drupal\Core\Path\AliasStorage
diff --git a/core/tests/Drupal/KernelTests/Core/Path/PathValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Path/PathValidatorTest.php
index 6e8042c8e7..001c4c51d3 100644
--- a/core/tests/Drupal/KernelTests/Core/Path/PathValidatorTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Path/PathValidatorTest.php
@@ -19,7 +19,7 @@ class PathValidatorTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['path', 'entity_test', 'user'];
+  protected static $modules = ['path', 'entity_test', 'user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Path/UrlAlterTest.php b/core/tests/Drupal/KernelTests/Core/Path/UrlAlterTest.php
index 37ac65ae8e..ae5f631c5f 100644
--- a/core/tests/Drupal/KernelTests/Core/Path/UrlAlterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Path/UrlAlterTest.php
@@ -17,7 +17,7 @@ class UrlAlterTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['path', 'url_alter_test', 'user'];
+  protected static $modules = ['path', 'url_alter_test', 'user'];
 
   public function testUrlWithQueryString() {
     // Test outbound query string altering.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php
index b0aece9a10..468e2c4563 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php
@@ -30,7 +30,7 @@ class ConditionTestDualUserTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'condition_test'];
+  protected static $modules = ['system', 'user', 'condition_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/CurrentThemeConditionTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/CurrentThemeConditionTest.php
index f75af9929d..54f9a09bd7 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/CurrentThemeConditionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/CurrentThemeConditionTest.php
@@ -15,7 +15,7 @@ class CurrentThemeConditionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'theme_test'];
+  protected static $modules = ['system', 'theme_test'];
 
   /**
    * Tests the current theme condition.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php
index e0a4a09952..b735d0c269 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php
@@ -19,7 +19,7 @@ class OptionalContextConditionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user', 'condition_test', 'node'];
+  protected static $modules = ['system', 'user', 'condition_test', 'node'];
 
   /**
    * Tests with both contexts mapped to the same user.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
index 68b6eb770e..41ed77c9de 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/RequestPathTest.php
@@ -42,7 +42,7 @@ class RequestPathTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'field', 'path'];
+  protected static $modules = ['system', 'user', 'field', 'path'];
 
   /**
    * The current path.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/ContextDefinitionTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/ContextDefinitionTest.php
index 842f76b456..d982030597 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/ContextDefinitionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/ContextDefinitionTest.php
@@ -16,7 +16,7 @@ class ContextDefinitionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test', 'user'];
+  protected static $modules = ['entity_test', 'user'];
 
   /**
    * @covers ::isSatisfiedBy
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/ContextPluginTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/ContextPluginTest.php
index 8a1fa4842f..4dde6c2c75 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/ContextPluginTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/ContextPluginTest.php
@@ -17,7 +17,7 @@
  */
 class ContextPluginTest extends KernelTestBase {
 
-  public static $modules = ['system', 'user', 'node', 'field', 'filter', 'text'];
+  protected static $modules = ['system', 'user', 'node', 'field', 'filter', 'text'];
 
   /**
    * Tests basic context definition and value getters and setters.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/DerivativeTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/DerivativeTest.php
index 519d7373c5..e80ce22b8b 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/DerivativeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/DerivativeTest.php
@@ -12,7 +12,7 @@ class DerivativeTest extends PluginTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * Tests getDefinitions() and getDefinition() with a derivativeDecorator.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/FactoryTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/FactoryTest.php
index ed7792982e..0178bb546a 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/FactoryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/FactoryTest.php
@@ -14,7 +14,7 @@ class FactoryTest extends PluginTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * Test that DefaultFactory can create a plugin instance.
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/InspectionTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/InspectionTest.php
index 20ba65c1bf..a737d9a5ef 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/InspectionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/InspectionTest.php
@@ -12,7 +12,7 @@ class InspectionTest extends PluginTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'user'];
+  protected static $modules = ['node', 'user'];
 
   /**
    * Ensure the test plugins correctly implement getPluginId() and getPluginDefinition().
diff --git a/core/tests/Drupal/KernelTests/Core/Plugin/PluginTestBase.php b/core/tests/Drupal/KernelTests/Core/Plugin/PluginTestBase.php
index 1d3734fae0..935b444c8e 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/PluginTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/PluginTestBase.php
@@ -20,7 +20,7 @@
    *
    * @var array
    */
-  public static $modules = ['plugin_test'];
+  protected static $modules = ['plugin_test'];
 
   protected $testPluginManager;
   protected $testPluginExpectedDefinitions;
diff --git a/core/tests/Drupal/KernelTests/Core/Queue/QueueSerializationTest.php b/core/tests/Drupal/KernelTests/Core/Queue/QueueSerializationTest.php
index b4e122b4b7..578b8b972a 100644
--- a/core/tests/Drupal/KernelTests/Core/Queue/QueueSerializationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Queue/QueueSerializationTest.php
@@ -30,7 +30,7 @@ class QueueSerializationTest extends KernelTestBase implements FormInterface {
    *
    * @var array
    */
-  public static $modules = ['system', 'user', 'aggregator'];
+  protected static $modules = ['system', 'user', 'aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Render/Element/ActionsTest.php b/core/tests/Drupal/KernelTests/Core/Render/Element/ActionsTest.php
index 135c7aabb1..70081bca9b 100644
--- a/core/tests/Drupal/KernelTests/Core/Render/Element/ActionsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Render/Element/ActionsTest.php
@@ -15,7 +15,7 @@ class ActionsTest extends KernelTestBase implements FormInterface {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php b/core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php
index 906e74bb6a..5d59f524fb 100644
--- a/core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php
@@ -18,7 +18,7 @@ class RenderElementTypesTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'router_test'];
+  protected static $modules = ['system', 'router_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Render/Element/TableTest.php b/core/tests/Drupal/KernelTests/Core/Render/Element/TableTest.php
index 6bf2faaa98..49426b0406 100644
--- a/core/tests/Drupal/KernelTests/Core/Render/Element/TableTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Render/Element/TableTest.php
@@ -16,7 +16,7 @@ class TableTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'form_test'];
+  protected static $modules = ['system', 'form_test'];
 
   /**
    * Tableheader.js provides 'sticky' table headers, and is included by default.
diff --git a/core/tests/Drupal/KernelTests/Core/Render/RenderCacheTest.php b/core/tests/Drupal/KernelTests/Core/Render/RenderCacheTest.php
index 91061ca67f..1d98ff42ce 100644
--- a/core/tests/Drupal/KernelTests/Core/Render/RenderCacheTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Render/RenderCacheTest.php
@@ -19,7 +19,7 @@ class RenderCacheTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'system'];
+  protected static $modules = ['user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Render/RenderTest.php b/core/tests/Drupal/KernelTests/Core/Render/RenderTest.php
index 043aae4445..b0e3d8094a 100644
--- a/core/tests/Drupal/KernelTests/Core/Render/RenderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Render/RenderTest.php
@@ -16,7 +16,7 @@ class RenderTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'common_test', 'theme_test'];
+  protected static $modules = ['system', 'common_test', 'theme_test'];
 
   /**
    * Tests theme preprocess functions being able to attach assets.
diff --git a/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteNoneTest.php b/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteNoneTest.php
index 6d26891fdb..c6dc92998c 100644
--- a/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteNoneTest.php
+++ b/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteNoneTest.php
@@ -22,7 +22,7 @@ class RouteNoneTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * The URL generator.
diff --git a/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteProcessorCurrentIntegrationTest.php b/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteProcessorCurrentIntegrationTest.php
index 4e42271aa5..bf9c5cdb43 100644
--- a/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteProcessorCurrentIntegrationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/RouteProcessor/RouteProcessorCurrentIntegrationTest.php
@@ -21,7 +21,7 @@ class RouteProcessorCurrentIntegrationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * The URL generator.
diff --git a/core/tests/Drupal/KernelTests/Core/Routing/ContentNegotiationRoutingTest.php b/core/tests/Drupal/KernelTests/Core/Routing/ContentNegotiationRoutingTest.php
index 34c6d5852a..7a8fcf4b02 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/ContentNegotiationRoutingTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/ContentNegotiationRoutingTest.php
@@ -17,7 +17,7 @@ class ContentNegotiationRoutingTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['conneg_test'];
+  protected static $modules = ['conneg_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Routing/ExceptionHandlingTest.php b/core/tests/Drupal/KernelTests/Core/Routing/ExceptionHandlingTest.php
index 5d68f95e79..ae81c1ae53 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/ExceptionHandlingTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/ExceptionHandlingTest.php
@@ -17,7 +17,7 @@ class ExceptionHandlingTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'router_test'];
+  protected static $modules = ['system', 'router_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php b/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php
index 44efa16479..b3b07e48c4 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php
@@ -37,7 +37,7 @@ class RouteProviderTest extends KernelTestBase {
   /**
    * Modules to enable.
    */
-  public static $modules = ['url_alter_test', 'system', 'language'];
+  protected static $modules = ['url_alter_test', 'system', 'language'];
 
   /**
    * A collection of shared fixture data for tests.
diff --git a/core/tests/Drupal/KernelTests/Core/Routing/UrlIntegrationTest.php b/core/tests/Drupal/KernelTests/Core/Routing/UrlIntegrationTest.php
index 053db792cb..8213800676 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/UrlIntegrationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/UrlIntegrationTest.php
@@ -19,7 +19,7 @@ class UrlIntegrationTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['user', 'router_test', 'system'];
+  protected static $modules = ['user', 'router_test', 'system'];
 
   /**
    * Ensures that the access() method on \Drupal\Core\Url objects works.
diff --git a/core/tests/Drupal/KernelTests/Core/ServiceProvider/ServiceProviderTest.php b/core/tests/Drupal/KernelTests/Core/ServiceProvider/ServiceProviderTest.php
index 970ea0486d..0411f5f83c 100644
--- a/core/tests/Drupal/KernelTests/Core/ServiceProvider/ServiceProviderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/ServiceProvider/ServiceProviderTest.php
@@ -16,7 +16,7 @@ class ServiceProviderTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['file', 'service_provider_test', 'system'];
+  protected static $modules = ['file', 'service_provider_test', 'system'];
 
   /**
    * Tests that services provided by module service providers get registered to the DIC.
diff --git a/core/tests/Drupal/KernelTests/Core/StringTranslation/TranslationStringTest.php b/core/tests/Drupal/KernelTests/Core/StringTranslation/TranslationStringTest.php
index d190cc5343..04b21f68f4 100644
--- a/core/tests/Drupal/KernelTests/Core/StringTranslation/TranslationStringTest.php
+++ b/core/tests/Drupal/KernelTests/Core/StringTranslation/TranslationStringTest.php
@@ -18,7 +18,7 @@ class TranslationStringTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
   ];
 
diff --git a/core/tests/Drupal/KernelTests/Core/TempStore/AnonymousPrivateTempStoreTest.php b/core/tests/Drupal/KernelTests/Core/TempStore/AnonymousPrivateTempStoreTest.php
index 7b1faa86cc..9b3922c4f2 100644
--- a/core/tests/Drupal/KernelTests/Core/TempStore/AnonymousPrivateTempStoreTest.php
+++ b/core/tests/Drupal/KernelTests/Core/TempStore/AnonymousPrivateTempStoreTest.php
@@ -17,7 +17,7 @@ class AnonymousPrivateTempStoreTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/TempStore/TempStoreDatabaseTest.php b/core/tests/Drupal/KernelTests/Core/TempStore/TempStoreDatabaseTest.php
index 2abe70760c..9134ce491f 100644
--- a/core/tests/Drupal/KernelTests/Core/TempStore/TempStoreDatabaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/TempStore/TempStoreDatabaseTest.php
@@ -21,7 +21,7 @@ class TempStoreDatabaseTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * A key/value store factory.
diff --git a/core/tests/Drupal/KernelTests/Core/Test/PhpUnitBridgeTest.php b/core/tests/Drupal/KernelTests/Core/Test/PhpUnitBridgeTest.php
index d82a37b906..2942eaace9 100644
--- a/core/tests/Drupal/KernelTests/Core/Test/PhpUnitBridgeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Test/PhpUnitBridgeTest.php
@@ -13,7 +13,7 @@
  */
 class PhpUnitBridgeTest extends KernelTestBase {
 
-  public static $modules = ['deprecation_test'];
+  protected static $modules = ['deprecation_test'];
 
   /**
    * @expectedDeprecation Drupal\deprecation_test\Deprecation\FixtureDeprecatedClass is deprecated.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ImageTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ImageTest.php
index 72cecce229..e005cc343c 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ImageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ImageTest.php
@@ -17,7 +17,7 @@ class ImageTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /*
    * The images to test with.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/MessageTest.php b/core/tests/Drupal/KernelTests/Core/Theme/MessageTest.php
index 1b3796eff4..688fbb85dc 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/MessageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/MessageTest.php
@@ -14,7 +14,7 @@ class MessageTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests setting messages output.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
index 320e92f46a..46770cd530 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
@@ -20,7 +20,7 @@ class RegistryTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test', 'system'];
+  protected static $modules = ['theme_test', 'system'];
 
   protected $profile = 'testing';
 
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/StableLibraryOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Theme/StableLibraryOverrideTest.php
index 1976b2684c..66d0838378 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/StableLibraryOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/StableLibraryOverrideTest.php
@@ -49,7 +49,7 @@ class StableLibraryOverrideTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php b/core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php
index 88bbde23a0..e33f7e72c8 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php
@@ -15,7 +15,7 @@ class StableTemplateOverrideTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'user'];
+  protected static $modules = ['system', 'user'];
 
   /**
    * An array of template names to skip, without the extension.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/StableThemeTest.php b/core/tests/Drupal/KernelTests/Core/Theme/StableThemeTest.php
index 8a79a9eff4..1d85402fa0 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/StableThemeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/StableThemeTest.php
@@ -16,7 +16,7 @@ class StableThemeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * The theme handler.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php
index dc606def66..994c721f4f 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php
@@ -19,7 +19,7 @@ class ThemeInstallerTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php
index 8bcc3c4bc9..c68ec3c094 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ThemeRenderAndAutoescapeTest.php
@@ -25,7 +25,7 @@ class ThemeRenderAndAutoescapeTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ThemeSettingsTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ThemeSettingsTest.php
index cf0e7d2c21..0726e42c8b 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ThemeSettingsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ThemeSettingsTest.php
@@ -18,7 +18,7 @@ class ThemeSettingsTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * List of discovered themes.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php b/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
index 1aaf40c4e0..d322a94d17 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
@@ -23,7 +23,7 @@ class TwigEnvironmentTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * Tests inline templates.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/TwigMarkupInterfaceTest.php b/core/tests/Drupal/KernelTests/Core/Theme/TwigMarkupInterfaceTest.php
index 826ac047cb..3948062f2b 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/TwigMarkupInterfaceTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TwigMarkupInterfaceTest.php
@@ -29,7 +29,7 @@ class TwigMarkupInterfaceTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
   ];
 
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/TwigWhiteListTest.php b/core/tests/Drupal/KernelTests/Core/Theme/TwigWhiteListTest.php
index 7af10f5946..a638169788 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/TwigWhiteListTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TwigWhiteListTest.php
@@ -35,7 +35,7 @@ class TwigWhiteListTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'taxonomy', 'user', 'system', 'text', 'field', 'entity_reference'];
+  protected static $modules = ['node', 'taxonomy', 'user', 'system', 'text', 'field', 'entity_reference'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/TypedData/TypedDataTest.php b/core/tests/Drupal/KernelTests/Core/TypedData/TypedDataTest.php
index 7771465307..0ffbf04f3b 100644
--- a/core/tests/Drupal/KernelTests/Core/TypedData/TypedDataTest.php
+++ b/core/tests/Drupal/KernelTests/Core/TypedData/TypedDataTest.php
@@ -38,7 +38,7 @@ class TypedDataTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system', 'field', 'file', 'user'];
+  protected static $modules = ['system', 'field', 'file', 'user'];
 
   protected function setUp() {
     parent::setup();
diff --git a/core/tests/Drupal/KernelTests/Core/Update/CompatibilityFixTest.php b/core/tests/Drupal/KernelTests/Core/Update/CompatibilityFixTest.php
index 20a45cad5c..9f11ea9f27 100644
--- a/core/tests/Drupal/KernelTests/Core/Update/CompatibilityFixTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Update/CompatibilityFixTest.php
@@ -14,7 +14,7 @@ class CompatibilityFixTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Url/LinkGenerationTest.php b/core/tests/Drupal/KernelTests/Core/Url/LinkGenerationTest.php
index 16452d0111..aa483c8f78 100644
--- a/core/tests/Drupal/KernelTests/Core/Url/LinkGenerationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Url/LinkGenerationTest.php
@@ -14,7 +14,7 @@
  */
 class LinkGenerationTest extends KernelTestBase {
 
-  public static $modules = ['link_generation_test'];
+  protected static $modules = ['link_generation_test'];
 
   /**
    * Tests how hook_link_alter() can affect escaping of the link text.
diff --git a/core/tests/Drupal/KernelTests/Core/Validation/ConstraintsTest.php b/core/tests/Drupal/KernelTests/Core/Validation/ConstraintsTest.php
index 8e17422ff6..0c5363f499 100644
--- a/core/tests/Drupal/KernelTests/Core/Validation/ConstraintsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Validation/ConstraintsTest.php
@@ -14,7 +14,7 @@ class ConstraintsTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['config_test'];
+  protected static $modules = ['config_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/RequestProcessing/RedirectOnExceptionTest.php b/core/tests/Drupal/KernelTests/RequestProcessing/RedirectOnExceptionTest.php
index c7eb3b226f..f4369ed7fa 100644
--- a/core/tests/Drupal/KernelTests/RequestProcessing/RedirectOnExceptionTest.php
+++ b/core/tests/Drupal/KernelTests/RequestProcessing/RedirectOnExceptionTest.php
@@ -16,7 +16,7 @@ class RedirectOnExceptionTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['system', 'test_page_test'];
+  protected static $modules = ['system', 'test_page_test'];
 
   /**
    * {@inheritdoc}