diff --git a/core/modules/action/tests/src/Functional/ActionListTest.php b/core/modules/action/tests/src/Functional/ActionListTest.php
index 309160f..07eb2df 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 5b01099..8c7e6ac 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 439ffe4..c6f3809 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 9b9dcf6..cc38484 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 bd87724..337f033 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 1737715..13a3c2c 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 0b1a2ca..13b3188 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 1601449..feadb44 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/migrate/source/ActionTest.php b/core/modules/action/tests/src/Kernel/Plugin/migrate/source/ActionTest.php
index 7f7b7ef..bafdeb4 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'];
+  protected static $modules = ['action', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/aggregator/src/Tests/AggregatorTestBase.php b/core/modules/aggregator/src/Tests/AggregatorTestBase.php
index f422489..f8b5e5c 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 37e6470..eb4a203 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 ddd98bb..92c6f91 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 7d75696..60c8771 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 dc0aab9..3a1e07b 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 7e3d672..fc2b805 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/ImportOpmlTest.php b/core/modules/aggregator/tests/src/Functional/ImportOpmlTest.php
index 2500b9e..68543bf 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 09da343..35c9a6a 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/Kernel/AggregatorTitleTest.php b/core/modules/aggregator/tests/src/Kernel/AggregatorTitleTest.php
index 4493c5c..374a2c1 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 d8804dd9..b3e10e4 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 e44bd4f..705c4b6 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 6d96aa1..5bf0dba 100644
--- a/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php
+++ b/core/modules/aggregator/tests/src/Kernel/Migrate/MigrateAggregatorStubTest.php
@@ -18,7 +18,7 @@ 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 280a103..a9a4355 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 9dac60f..eef5ba4 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 5343d1e..d14846c 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 fd20823..e4dbe34 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 83e59d9..8dde35b 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 0fa8f63..9e2eb36 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 d41f4f4..67fe136 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 09101f7..ea9206a 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 d0ca46e..2d5a5f5 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 a095d3c..a016467 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 39f57b2..be9d149 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 778f3db..92ebcdf 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 48f35a7..d673ec5 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 267cc34..7ce8f73 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 b197a76..f2c1afe 100644
--- a/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php
+++ b/core/modules/basic_auth/tests/src/Functional/BasicAuthTest.php
@@ -22,7 +22,7 @@ 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 92d1a86..14e80a9 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 b4da7b0..9a4a9c2 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 JavascriptTestBase {
   /**
    * {@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 7397a47..8419db7 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 88f35e4..3189e67 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 e5bb360..6413e50 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 884b587..5977531 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 c0e7f58..ea5702b 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 c515515..4b3244f 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 3a5c1ff..054da59 100644
--- a/core/modules/block/tests/src/Functional/BlockHookOperationTest.php
+++ b/core/modules/block/tests/src/Functional/BlockHookOperationTest.php
@@ -17,7 +17,7 @@ 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 5f9afe9..b2426e4 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 fe8cdcb..c7425fa 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 b9c7c90..8c1b932 100644
--- a/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php
+++ b/core/modules/block/tests/src/Functional/BlockLanguageCacheTest.php
@@ -18,7 +18,7 @@ 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 cf1b877..86bfec1 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 2fd1ab8..e066860 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 89ce0c4..27cf5bc 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 fd4fd51..fe0f7bb 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 e1ccd1a..725c04d 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 e6c1875..b5e818e 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 3e661d7..7eea081 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/NewDefaultThemeBlocksTest.php b/core/modules/block/tests/src/Functional/NewDefaultThemeBlocksTest.php
index adc7da3..b3353ae 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 7b7927d..1e9bed9 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/Views/DisplayBlockTest.php b/core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
index 0a18d7f..fd3a1d1 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 5cea220..ecc6a03 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 JavascriptTestBase {
   /**
    * {@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 2bf41e0..cfd9a46 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 48d63a3..6e1a4d2 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 33de12c..9e2611e 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 2a7c771..5a54808 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 71c4f55..05164de 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/MigrateBlockTest.php b/core/modules/block/tests/src/Kernel/Migrate/d6/MigrateBlockTest.php
index bb59f50..03b8c43 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 6f07dc9..8028cbc 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 d37f8c7..1c47f82 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_content/src/Tests/BlockContentTestBase.php b/core/modules/block_content/src/Tests/BlockContentTestBase.php
index 3794478..fc28dbc 100644
--- a/core/modules/block_content/src/Tests/BlockContentTestBase.php
+++ b/core/modules/block_content/src/Tests/BlockContentTestBase.php
@@ -40,7 +40,7 @@
    *
    * @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 3ea2dba..b23a386 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 59f111b..8a5dc7c 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/BlockContentCreationTest.php b/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
index 0f89b86..773eb07 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentCreationTest.php
@@ -21,7 +21,7 @@ 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 aba60c3..a63f393 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentListTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentListTest.php
@@ -18,7 +18,7 @@ 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 1c623be..b3b0f9d 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentListViewsTest.php
@@ -16,7 +16,7 @@ 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 355faf1..5e773e9 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 0f7ae5a..048bfe2 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 45c7e26..9f69597 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentTestBase.php
@@ -37,7 +37,7 @@
    *
    * @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 2699fcf..22c96d7 100644
--- a/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php
+++ b/core/modules/block_content/tests/src/Functional/BlockContentTranslationUITest.php
@@ -19,7 +19,7 @@ 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 6c76a90..002f966 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/UnpublishedBlockTest.php b/core/modules/block_content/tests/src/Functional/UnpublishedBlockTest.php
index 026b0e5..160d9c6 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 a016ab9..d304a54 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 10ce140..d283a1b 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 ffce5886..3f054fb 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/RevisionRelationshipsTest.php b/core/modules/block_content/tests/src/Functional/Views/RevisionRelationshipsTest.php
index 0ccebd2..f5240c4 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/BlockContentDeletionTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentDeletionTest.php
index e54b2d3..2274750 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/Migrate/MigrateBlockContentBodyFieldTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/MigrateBlockContentBodyFieldTest.php
index 7d34373..d09a26b 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 5eb9e41..1cd4b35 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 8fed905..314e412 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 1958039..a6356ed 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 4accc20..e8ab991 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 bb5ba89..aa55668 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/d7/MigrateCustomBlockTest.php b/core/modules/block_content/tests/src/Kernel/Migrate/d7/MigrateCustomBlockTest.php
index 706a7cc..edab676 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 22ab03c..7f84eb5 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/d7/BlockCustomTest.php b/core/modules/block_content/tests/src/Kernel/Plugin/migrate/source/d7/BlockCustomTest.php
index 55419e3..3a2e02d 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 8e89048..919be0c 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 a863ff1..40ed9da 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 5d6a340..2f5a082 100644
--- a/core/modules/book/tests/src/Functional/BookContentModerationTest.php
+++ b/core/modules/book/tests/src/Functional/BookContentModerationTest.php
@@ -19,7 +19,7 @@ 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 b5658bd..be0ee9a 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 d02dfd5..0097c1f 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 9ee79c7..41d626f 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 d8d406b..79e7f6e 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 JavascriptTestBase {
   /**
    * {@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 ababb3d..516b1e1 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 9430991..732f3ce 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 becf87d..eae2c69 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'];
 
   /**
    * {@inheritdoc}
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 cab65e3..28168f8 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/Plugin/migrate/source/d6/BookTest.php b/core/modules/book/tests/src/Kernel/Plugin/migrate/source/d6/BookTest.php
index feece1f..407ef15 100644
--- a/core/modules/book/tests/src/Kernel/Plugin/migrate/source/d6/BookTest.php
+++ b/core/modules/book/tests/src/Kernel/Plugin/migrate/source/d6/BookTest.php
@@ -13,7 +13,7 @@ class BookTest extends MigrateSqlSourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['book', 'migrate_drupal'];
+  protected static $modules = ['book', 'migrate_drupal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php b/core/modules/breakpoint/tests/src/Kernel/BreakpointDiscoveryTest.php
index dc81757..725d858 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/modules/src/Kernel/CKEditorPluginManagerTest.php b/core/modules/ckeditor/tests/modules/src/Kernel/CKEditorPluginManagerTest.php
index eb02d37..660288c 100644
--- a/core/modules/ckeditor/tests/modules/src/Kernel/CKEditorPluginManagerTest.php
+++ b/core/modules/ckeditor/tests/modules/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/modules/src/Kernel/CKEditorTest.php b/core/modules/ckeditor/tests/modules/src/Kernel/CKEditorTest.php
index 4f1da31..e937964 100644
--- a/core/modules/ckeditor/tests/modules/src/Kernel/CKEditorTest.php
+++ b/core/modules/ckeditor/tests/modules/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/Functional/CKEditorAdminTest.php b/core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php
index 1ec2227..3b69f18 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 cad0947..213a417 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 9f41834..75e62fe 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 c47b67b..631b10e 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 b15433d..f95df40 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 JavascriptTestBase {
   /**
    * {@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 80de46d..a777411 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 JavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'ckeditor', 'filter'];
+  protected static $modules = ['node', 'ckeditor', 'filter'];
 
   /**
    * {@inheritdoc}
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 aecc228..afd916b 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 f93f358..8793151 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 9f6914c..c13a403 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 c11a922..fff078f 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/comment/src/Tests/CommentCacheTagsTest.php b/core/modules/comment/src/Tests/CommentCacheTagsTest.php
index 12e0ef8..c041e87 100644
--- a/core/modules/comment/src/Tests/CommentCacheTagsTest.php
+++ b/core/modules/comment/src/Tests/CommentCacheTagsTest.php
@@ -24,7 +24,7 @@ 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/src/Tests/CommentNewIndicatorTest.php b/core/modules/comment/src/Tests/CommentNewIndicatorTest.php
index 318e17c..19f8253 100644
--- a/core/modules/comment/src/Tests/CommentNewIndicatorTest.php
+++ b/core/modules/comment/src/Tests/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/src/Tests/CommentTestBase.php b/core/modules/comment/src/Tests/CommentTestBase.php
index 3b923ff..efe90e5 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 3d10858..85546c3 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/CommentActionsTest.php b/core/modules/comment/tests/src/Functional/CommentActionsTest.php
index 79786fc..76a561c 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 db7d1bd..f8bdb70 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 45693b5..118357b 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/CommentFieldsTest.php b/core/modules/comment/tests/src/Functional/CommentFieldsTest.php
index 2df9973..b2485f8 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 ce9a9ab..2eb750b 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 e49361b..259dd48 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 3d79d96..b9f233c 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/CommentNodeAccessTest.php b/core/modules/comment/tests/src/Functional/CommentNodeAccessTest.php
index 6842dc1..3decbf8 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 5889d69..b3cf798 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 60708bd..2a56056 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 d2495d3..094f1e6 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 7cadcbf..bd77212 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 a7fe6b5..ad4d8e2 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 daac938..5f27f3f 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 6e0c8a2..7779b44 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/Views/CommentFieldFilterTest.php b/core/modules/comment/tests/src/Functional/Views/CommentFieldFilterTest.php
index dabacc3..ec43ab7 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 17e04b5..c826e56 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 a9444a2..b3995af 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 5cb9680..2f333c4 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 e2c5d15..ae8981a 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 62fada9..1a39723 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'];
 
 
   /**
diff --git a/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php b/core/modules/comment/tests/src/Kernel/CommentBundlesTest.php
index d907233..b46e12f 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 bdea71d..6ec7323 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 1e0fd72..017e66b 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 af73034..c327d54 100644
--- a/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php
+++ b/core/modules/comment/tests/src/Kernel/CommentIntegrationTest.php
@@ -21,7 +21,7 @@ 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 1a7fc65..f2f200b 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 adbe1b0..6a8a93c 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 98b7715..f28e1e4 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 0b256ea..b719ba2 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/MigrateCommentStubTest.php
@@ -20,7 +20,7 @@ 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 2c13371..2341aea 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 74a8715..be7d16c 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 c9e0d6b..cc4b384 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 03469c4..f0a6592 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 e08e2d2..7974cc0 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 06ca655..21c0f75 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 2fa6082..339d8f8 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 aeb1e92..42cac7d 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 2c3025a..372dbcf 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 2f0f6f3..2715251 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 4b928f7..4f49ac4 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 aa59f67..5d4e19b 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 95717ed..68b9f0f 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 = ['filter', 'node', 'comment', 'text', 'menu_ui'];
+  protected static $modules = ['filter', 'node', 'comment', 'text', 'menu_ui'];
 
   /**
    * {@inheritdoc}
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 b0c96da..2eb5b41 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 a4d91c4..38099d1 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 0372f0f..e32b9d3 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 dd1b1fd..895ed97 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 a84c776..74cc6b7 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 9d9760b..3316543 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 11f3db5..6355c16 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 86e8949..fc8d21c 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/CommentUserNameTest.php b/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
index e1b3c94..662a740 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentUserNameTest.php
@@ -26,7 +26,7 @@ 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 f807c58..bc2a479 100644
--- a/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php
+++ b/core/modules/comment/tests/src/Kernel/Views/CommentViewsFieldAccessTest.php
@@ -16,7 +16,7 @@ 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 5167503..e112b8a 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/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php b/core/modules/config/tests/src/Functional/CacheabilityMetadataConfigOverrideIntegrationTest.php
index f2f8730..f263255 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 696a36e..052a245 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 7482935..8a60449 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 a4dc92c..6e83d16 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 7c5fa1f..8f16b1e 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 ae9be13..3f9b2df 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 af68f33..4da9f8c 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 5b237c4..a34a4ac 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 96a80a6..c21a08b 100644
--- a/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php
+++ b/core/modules/config/tests/src/Functional/ConfigExportImportUITest.php
@@ -67,7 +67,7 @@ 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 d92071e..4370dd0 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 8b0787d..190157c 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 fd76990..4bb9463 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 955842d..7fcafca 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 092ad2b..1035b87 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 dc10323..1cfedf6 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 6c4e1bb..db5c45c 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 189d78f..35270be 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 110c9f8..9e2bc32 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 JavascriptTestBase {
   /**
    * {@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_translation/tests/src/Functional/ConfigTranslationCacheTest.php b/core/modules/config_translation/tests/src/Functional/ConfigTranslationCacheTest.php
index 0def24a..40fcc70 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 95af49e..8fb5103 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 4698b05..aad2404 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 586d197..123a23d 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationListUiTest.php
@@ -26,7 +26,7 @@ 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 55b02dc..a147c92 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 1d8d859..3638034 100644
--- a/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/tests/src/Functional/ConfigTranslationUiTest.php
@@ -30,7 +30,7 @@ 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 dcfb791..6096742 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 edb41f9..f035d46 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 13e1b54..94461ff 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 JavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'config_translation',
     'contextual',
     'node',
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 37cd4a9..781f3a7 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 = ['language', 'config_translation'];
+  protected static $modules = ['language', 'config_translation'];
 
   /**
    * {@inheritdoc}
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 326e1bb..02f32fe 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 = ['language', 'config_translation'];
+  protected static $modules = ['language', 'config_translation'];
 
   /**
    * {@inheritdoc}
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 bc622e1..919dc2f 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 = ['language', 'locale', 'config_translation'];
+  protected static $modules = ['language', 'locale', 'config_translation'];
 
   /**
    * {@inheritdoc}
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 01d5ec9..b9973ba 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 = ['config_translation', 'locale', 'language', 'field'];
+  protected static $modules = ['config_translation', 'locale', 'language', 'field'];
 
   /**
    * Tests migration of translated user profile fields.
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 b783acc..0aa45ff 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 02cdd99..fd6b92a 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 0c34884..79e1f79 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 8304d7c..41f3f16 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 178a3ad..0afe593 100644
--- a/core/modules/contact/tests/src/Functional/ContactSitewideTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactSitewideTest.php
@@ -28,7 +28,7 @@ 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 acacab4..c9a8b1a 100644
--- a/core/modules/contact/tests/src/Functional/ContactStorageTest.php
+++ b/core/modules/contact/tests/src/Functional/ContactStorageTest.php
@@ -23,7 +23,7 @@ class ContactStorageTest extends ContactSitewideTest {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'text',
     'contact',
diff --git a/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php b/core/modules/contact/tests/src/Functional/Views/ContactFieldsTest.php
index c66b5ad..397d24d 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 c3b68f0..7057d92 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 e7343b9..de556c0 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 ffadad4..6eabda2 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 073a670..afadb04 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 22385f0..b94cdf0 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 619e0cd..1ea9b33 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 72ea7f2..5abac5a 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 195718a..88c9170 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',
   ];
diff --git a/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php b/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
index 32d10fa..962c24b 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationActionsTest.php
@@ -21,7 +21,7 @@ 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 326eb7c..7bbf651 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationFormTest.php
@@ -16,7 +16,7 @@ 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 3104450..961df4e 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationLocaleTest.php
@@ -14,7 +14,7 @@ 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 703c10f..5a59f89 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationRevisionRevertTest.php
@@ -20,7 +20,7 @@ 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 304dcb5..d63d3e2 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationStateAccessTest.php
@@ -17,7 +17,7 @@ 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 92f51a8..6b293e8 100644
--- a/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php
+++ b/core/modules/content_moderation/tests/src/Functional/ModerationStateTestBase.php
@@ -48,7 +48,7 @@
    *
    * @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 ea79c2d..1327ff9 100644
--- a/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php
+++ b/core/modules/content_moderation/tests/src/Functional/NodeAccessTest.php
@@ -14,7 +14,7 @@ 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/Kernel/ContentModerationPermissionsTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationPermissionsTest.php
index f17e4ac..ba78fc5 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 4d10672..f308f1f 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 cc09e59..1c5fd3e 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 content_moderation_rest_resource_alter()
diff --git a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
index af59651..c82369e 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateStorageSchemaTest.php
@@ -19,7 +19,7 @@ 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 e52bf96..ed89cdb 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php
@@ -24,7 +24,7 @@ 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 931056e..9d53402 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ContentModerationWorkflowConfigTest.php
@@ -18,7 +18,7 @@ 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 e10756c..b0582d5 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 84bade4..f53c9f2 100644
--- a/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/DefaultRevisionStateTest.php
@@ -18,7 +18,7 @@ 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 1821744..3bfb5fa 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityOperationsTest.php
@@ -17,7 +17,7 @@ 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 3deaffa..8313433 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityRevisionConverterTest.php
@@ -15,7 +15,7 @@
  */
 class EntityRevisionConverterTest extends KernelTestBase {
 
-  public static $modules = [
+  protected static $modules = [
     'user',
     'entity_test',
     'system',
diff --git a/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php b/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
index 2fefc01..aaaf6d7 100644
--- a/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/EntityStateChangeValidationTest.php
@@ -17,7 +17,7 @@ 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 a5791c8..5be628b 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 3db6a66..6c2a528 100644
--- a/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/InitialStateTest.php
@@ -18,7 +18,7 @@ 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/ModerationStateFieldItemListTest.php b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
index a0d46da..1a68b8c 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationStateFieldItemListTest.php
@@ -17,7 +17,7 @@ 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 c40e753..14534d3 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ModerationStateWidgetTest.php
@@ -21,7 +21,7 @@ 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/StateFormatterTest.php b/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
index c32123d..58f0dea 100644
--- a/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/StateFormatterTest.php
@@ -19,7 +19,7 @@ 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 125d68f..9e136c5 100644
--- a/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php
+++ b/core/modules/content_moderation/tests/src/Kernel/ViewsDataIntegrationTest.php
@@ -18,7 +18,7 @@ class ViewsDataIntegrationTest extends ViewsKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'content_moderation_test_views',
     'node',
     'content_moderation',
diff --git a/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php b/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
index a84bb73..8f4dead 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 0b1de0b..93f2eb1 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 b85c3aa..83c8562 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 6dffed7..d78b76f 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 a3cc4e9..797bcfb 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 163b5e8..422ccb7 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 ae326ef..7e987ac 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationLanguageChangeTest.php
@@ -17,7 +17,7 @@ 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 8ea652e..0c8170d 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 bbad25c..a3350f3 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 2ec190d..15a7fe7 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/ContentTranslationSettingsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationSettingsTest.php
index f15a8f9..7c60629 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 c6a72a3..19e02ed 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 5f7c9fd..4910ef4 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 ec7f87d..d7436cc 100644
--- a/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php
+++ b/core/modules/content_translation/tests/src/Functional/ContentTranslationTestBase.php
@@ -18,7 +18,7 @@
    *
    * @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 77c176e..b7e9a35 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/ContentTranslationWorkflowsTest.php b/core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
index 759bd6d..ff9f7d8 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 4b4d53a..d713c60 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 d2e9e0d..d75201e 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 b095399..40572a2 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 JavascriptTestBase {
   /**
    * {@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 b8776a2..2a5b0e4 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/ContentTranslationSettingsApiTest.php b/core/modules/content_translation/tests/src/Kernel/ContentTranslationSettingsApiTest.php
index 3626045..40a7220 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 fa5fd1c..100d992 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/contextual/src/Tests/ContextualDynamicContextTest.php b/core/modules/contextual/src/Tests/ContextualDynamicContextTest.php
index 00ade5a..afc69b9 100644
--- a/core/modules/contextual/src/Tests/ContextualDynamicContextTest.php
+++ b/core/modules/contextual/src/Tests/ContextualDynamicContextTest.php
@@ -42,7 +42,7 @@ class ContextualDynamicContextTest extends WebTestBase {
    *
    * @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 de83692..7432184 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 JavascriptTestBase {
   /**
    * {@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 dc978aa..dd6964a 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 JavascriptTestBase {
   /**
    * {@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 f42bf20..c75fb5d 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 ca43b8d..fb803fe 100644
--- a/core/modules/datetime/src/Tests/DateTestBase.php
+++ b/core/modules/datetime/src/Tests/DateTestBase.php
@@ -26,7 +26,7 @@
    *
    * @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 0f068ab..36de5a3 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 21bad50..b6f81a8 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 1051ce4..3216ac8 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 ffce48c..6c1d66f 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 a65d439..77c0d04 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 75f892a..90768ff 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 f0c9c78..5ff8708 100644
--- a/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php
+++ b/core/modules/datetime/tests/src/Kernel/Views/DateTimeHandlerTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@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 bd83b98..09e7843 100644
--- a/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php
+++ b/core/modules/datetime_range/tests/src/Functional/DateRangeFieldTest.php
@@ -26,7 +26,7 @@ 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 54f805f..82f5c47 100644
--- a/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php
+++ b/core/modules/datetime_range/tests/src/Kernel/DateRangeItemTest.php
@@ -34,7 +34,7 @@ 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 155bb61..f820194 100644
--- a/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php
+++ b/core/modules/datetime_range/tests/src/Kernel/SeparatorTranslationTest.php
@@ -36,7 +36,7 @@ class SeparatorTranslationTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'datetime',
     'datetime_range',
     'entity_test',
diff --git a/core/modules/dblog/src/Tests/Rest/DbLogResourceTest.php b/core/modules/dblog/src/Tests/Rest/DbLogResourceTest.php
index 44dbe99..661ac52 100644
--- a/core/modules/dblog/src/Tests/Rest/DbLogResourceTest.php
+++ b/core/modules/dblog/src/Tests/Rest/DbLogResourceTest.php
@@ -18,7 +18,7 @@ class DbLogResourceTest extends RESTTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal', 'dblog'];
+  protected static $modules = ['hal', 'dblog'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php b/core/modules/dblog/tests/src/Functional/ConnectionFailureTest.php
index 37c855a..0b951b6 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/DbLogTest.php b/core/modules/dblog/tests/src/Functional/DbLogTest.php
index 5b82282..6fa8eb8 100644
--- a/core/modules/dblog/tests/src/Functional/DbLogTest.php
+++ b/core/modules/dblog/tests/src/Functional/DbLogTest.php
@@ -24,7 +24,7 @@ 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 d04d9ba..62d580d 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 ce7490f..26267c4 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 48ed396..31e1db2 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 73a6d83..1e0cfd3 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 d970830..ba94f66 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 67d693f..ecf3843 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/src/Tests/EditorAdminTest.php b/core/modules/editor/src/Tests/EditorAdminTest.php
index 4315a6d..3834832 100644
--- a/core/modules/editor/src/Tests/EditorAdminTest.php
+++ b/core/modules/editor/src/Tests/EditorAdminTest.php
@@ -20,7 +20,7 @@ class EditorAdminTest extends WebTestBase {
    *
    * @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/src/Tests/EditorLoadingTest.php b/core/modules/editor/src/Tests/EditorLoadingTest.php
index b8dd074..502e95b 100644
--- a/core/modules/editor/src/Tests/EditorLoadingTest.php
+++ b/core/modules/editor/src/Tests/EditorLoadingTest.php
@@ -20,7 +20,7 @@ class EditorLoadingTest extends WebTestBase {
    *
    * @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/src/Tests/EditorSecurityTest.php b/core/modules/editor/src/Tests/EditorSecurityTest.php
index cf9ab8f..6d68aa2 100644
--- a/core/modules/editor/src/Tests/EditorSecurityTest.php
+++ b/core/modules/editor/src/Tests/EditorSecurityTest.php
@@ -40,7 +40,7 @@ class EditorSecurityTest extends WebTestBase {
    *
    * @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/src/Tests/EditorUploadImageScaleTest.php b/core/modules/editor/src/Tests/EditorUploadImageScaleTest.php
index 5ac88c7..4e6779a 100644
--- a/core/modules/editor/src/Tests/EditorUploadImageScaleTest.php
+++ b/core/modules/editor/src/Tests/EditorUploadImageScaleTest.php
@@ -18,7 +18,7 @@ class EditorUploadImageScaleTest extends WebTestBase {
    *
    * @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/src/Tests/QuickEditIntegrationLoadingTest.php b/core/modules/editor/src/Tests/QuickEditIntegrationLoadingTest.php
index a4515d5..a260c5c 100644
--- a/core/modules/editor/src/Tests/QuickEditIntegrationLoadingTest.php
+++ b/core/modules/editor/src/Tests/QuickEditIntegrationLoadingTest.php
@@ -19,7 +19,7 @@ class QuickEditIntegrationLoadingTest extends WebTestBase {
    *
    * @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/EditorDialogAccessTest.php b/core/modules/editor/tests/src/Functional/EditorDialogAccessTest.php
index 3a97b35..06c3b9c 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/EditorPrivateFileReferenceFilterTest.php b/core/modules/editor/tests/src/Functional/EditorPrivateFileReferenceFilterTest.php
index 816de5d..0d5c75f 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/Kernel/EditorFileReferenceFilterTest.php b/core/modules/editor/tests/src/Kernel/EditorFileReferenceFilterTest.php
index a70a232..adc3e0b 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 aac665d..89ea85f 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 30f36e5..ede2b00 100644
--- a/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php
+++ b/core/modules/editor/tests/src/Kernel/EditorFilterIntegrationTest.php
@@ -17,7 +17,7 @@ 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 6500d1a..9b59d40 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 d1d6eaf..f40f649 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 276f559..ab0dc8a 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/Boolean/BooleanFieldTest.php b/core/modules/field/src/Tests/Boolean/BooleanFieldTest.php
index 6fc6c6d..c7e9d69 100644
--- a/core/modules/field/src/Tests/Boolean/BooleanFieldTest.php
+++ b/core/modules/field/src/Tests/Boolean/BooleanFieldTest.php
@@ -20,7 +20,7 @@ class BooleanFieldTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'entity_test',
     'field_ui',
     'options',
diff --git a/core/modules/field/src/Tests/Boolean/BooleanFormatterSettingsTest.php b/core/modules/field/src/Tests/Boolean/BooleanFormatterSettingsTest.php
index 92efa98..f75cbef 100644
--- a/core/modules/field/src/Tests/Boolean/BooleanFormatterSettingsTest.php
+++ b/core/modules/field/src/Tests/Boolean/BooleanFormatterSettingsTest.php
@@ -20,7 +20,7 @@ class BooleanFormatterSettingsTest extends WebTestBase {
    *
    * @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/src/Tests/Email/EmailFieldTest.php b/core/modules/field/src/Tests/Email/EmailFieldTest.php
index 269d91f..bf3290e 100644
--- a/core/modules/field/src/Tests/Email/EmailFieldTest.php
+++ b/core/modules/field/src/Tests/Email/EmailFieldTest.php
@@ -20,7 +20,7 @@ class EmailFieldTest extends WebTestBase {
    *
    * @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/src/Tests/EntityReference/EntityReferenceAdminTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
index fa68cb6..12baeab 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceAdminTest.php
@@ -28,7 +28,7 @@ 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/EntityReference/EntityReferenceFileUploadTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceFileUploadTest.php
index 1957584..eeb4bef 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceFileUploadTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceFileUploadTest.php
@@ -14,7 +14,7 @@
  */
 class EntityReferenceFileUploadTest extends WebTestBase {
 
-  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/src/Tests/FieldDefaultValueCallbackTest.php b/core/modules/field/src/Tests/FieldDefaultValueCallbackTest.php
index b6926ce..18f0fdb 100644
--- a/core/modules/field/src/Tests/FieldDefaultValueCallbackTest.php
+++ b/core/modules/field/src/Tests/FieldDefaultValueCallbackTest.php
@@ -18,7 +18,7 @@ class FieldDefaultValueCallbackTest extends WebTestBase {
    *
    * @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/src/Tests/FieldImportDeleteUninstallUiTest.php b/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php
index e353086..0473b5d 100644
--- a/core/modules/field/src/Tests/FieldImportDeleteUninstallUiTest.php
+++ b/core/modules/field/src/Tests/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/src/Tests/FormTest.php b/core/modules/field/src/Tests/FormTest.php
index 786e367..5583bba 100644
--- a/core/modules/field/src/Tests/FormTest.php
+++ b/core/modules/field/src/Tests/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/src/Tests/NestedFormTest.php b/core/modules/field/src/Tests/NestedFormTest.php
index 0bbfb0d..4e7ab8b 100644
--- a/core/modules/field/src/Tests/NestedFormTest.php
+++ b/core/modules/field/src/Tests/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/src/Tests/Number/NumberFieldTest.php b/core/modules/field/src/Tests/Number/NumberFieldTest.php
index 64da6c1..de1b8d2 100644
--- a/core/modules/field/src/Tests/Number/NumberFieldTest.php
+++ b/core/modules/field/src/Tests/Number/NumberFieldTest.php
@@ -20,7 +20,7 @@ class NumberFieldTest extends WebTestBase {
    *
    * @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/src/Tests/String/StringFieldTest.php b/core/modules/field/src/Tests/String/StringFieldTest.php
index 97e470e..77e7fc3 100644
--- a/core/modules/field/src/Tests/String/StringFieldTest.php
+++ b/core/modules/field/src/Tests/String/StringFieldTest.php
@@ -20,7 +20,7 @@ class StringFieldTest extends WebTestBase {
    *
    * @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/src/Tests/Views/FieldTestBase.php b/core/modules/field/src/Tests/Views/FieldTestBase.php
index f04e19f..d730146 100644
--- a/core/modules/field/src/Tests/Views/FieldTestBase.php
+++ b/core/modules/field/src/Tests/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/src/Tests/Views/FieldUITest.php b/core/modules/field/src/Tests/Views/FieldUITest.php
index 851b7bd..8b6dcf4 100644
--- a/core/modules/field/src/Tests/Views/FieldUITest.php
+++ b/core/modules/field/src/Tests/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/src/Tests/Views/HandlerFieldFieldTest.php b/core/modules/field/src/Tests/Views/HandlerFieldFieldTest.php
index dfbb89b..b6daae9 100644
--- a/core/modules/field/src/Tests/Views/HandlerFieldFieldTest.php
+++ b/core/modules/field/src/Tests/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/src/Tests/reEnableModuleFieldTest.php b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
index 24c0eff..e6ac9e9 100644
--- a/core/modules/field/src/Tests/reEnableModuleFieldTest.php
+++ b/core/modules/field/src/Tests/reEnableModuleFieldTest.php
@@ -18,7 +18,7 @@ class reEnableModuleFieldTest extends WebTestBase {
    *
    * @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/Functional/EntityReference/EntityReferenceAutoCreateTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
index 1e6511f..0d0bd59 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceAutoCreateTest.php
@@ -20,7 +20,7 @@ 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 4567bd0..7d587e9 100644
--- a/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php
+++ b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceFieldDefaultValueTest.php
@@ -23,7 +23,7 @@ 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 7ded590..01b9086 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/EntityReferenceIntegrationTest.php b/core/modules/field/tests/src/Functional/EntityReference/EntityReferenceIntegrationTest.php
index ea65c4b..ea1fa89 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 cfb5ecf..02514ec 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 c7f234f..a7e4f7c 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/FieldHelpTest.php b/core/modules/field/tests/src/Functional/FieldHelpTest.php
index 9a6ff67..fc45704 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/TranslationWebTest.php b/core/modules/field/tests/src/Functional/TranslationWebTest.php
index 19af64d..475af79 100644
--- a/core/modules/field/tests/src/Functional/TranslationWebTest.php
+++ b/core/modules/field/tests/src/Functional/TranslationWebTest.php
@@ -19,7 +19,7 @@ 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/FunctionalJavascript/FormJSAddMoreTest.php b/core/modules/field/tests/src/FunctionalJavascript/FormJSAddMoreTest.php
index 64ee24d..494bd7f 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 JavascriptTestBase {
   /**
    * {@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 94f5bc6..c6c389e 100644
--- a/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/Boolean/BooleanFormatterTest.php
@@ -22,7 +22,7 @@ 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 3cbf63e..556c789 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 05db0dc..3ad6a9a 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 391d8db..f769a7b 100644
--- a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
+++ b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
@@ -37,7 +37,7 @@ 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 780fe7b..1eaea1e 100644
--- a/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php
+++ b/core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceSettingsTest.php
@@ -21,7 +21,7 @@ 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 5f4c8ee..ebb4b74 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 85d6b0b..b56f9b7 100644
--- a/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldDefinitionIntegrityTest.php
@@ -16,7 +16,7 @@ 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/FieldImportChangeTest.php b/core/modules/field/tests/src/Kernel/FieldImportChangeTest.php
index 9b83919..a8aac0d 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 f3408a5..6773423 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 c3a4d3c..9ef6461 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 6bc40cc..ea54932 100644
--- a/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
+++ b/core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
@@ -19,7 +19,7 @@
    *
    * @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 a24bedb..b5024d0 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 7bf3ad5..27a5478 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 6c4e29c..67d56d7 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 6e8e040..2bbec24 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 576e86a..89a575b 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 2c4cdab..14243ae 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 ee4d204..284cb36 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 272af0e..2785518 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 0a7e9dc..27deaec 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 ba47d91..d885a03 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 a4ef2f6..b1c2a6a 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 baea562..e46d00b 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 bfbddca..2fd757f 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 0602641..e83d05e 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 0663b91..12745e9 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 e3faee4..1c65c8a 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 895fe3f..3011ed8 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 f904429..6be4de5 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 deab066..15f6a4c 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 80ab04f..181e479 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 1000d64..030ba2d 100644
--- a/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/String/RawStringFormatterTest.php
@@ -23,7 +23,7 @@ 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 b09eb58..95c1293 100644
--- a/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/String/StringFormatterTest.php
@@ -23,7 +23,7 @@ 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 0eeb778..4059cc6 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 73a9948..a17401e 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 d1a269a..896cd5a 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 1ac87fc..0d58240 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 f71be31..8b36ca6 100644
--- a/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
+++ b/core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
@@ -21,7 +21,7 @@ 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 124fd94..e697863 100644
--- a/core/modules/field/tests/src/Kernel/TranslationTest.php
+++ b/core/modules/field/tests/src/Kernel/TranslationTest.php
@@ -23,7 +23,7 @@ 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 9bab0b5..01bc313 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 162d223..f929a86 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 JavascriptTestBase {
   /**
    * {@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 631d336..73c588a 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 750a327..ec012c2 100644
--- a/core/modules/field_ui/src/Tests/ManageDisplayTest.php
+++ b/core/modules/field_ui/src/Tests/ManageDisplayTest.php
@@ -25,7 +25,7 @@ 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 d08ab03..6723652 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 78764fb..720087e 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'];
+  protected static $modules = ['block', 'entity_test', 'field_ui'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php b/core/modules/field_ui/tests/src/Functional/EntityDisplayTest.php
index c9cfc05..b9f7540 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 1f66c9a..b5d43c8 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 fe7a270..0eb75e9 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 1c21b06..a4566ab 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 ae2c56c..2640650 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 JavascriptTestBase {
   /**
    * {@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 2d02e44..43338ce 100644
--- a/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php
+++ b/core/modules/field_ui/tests/src/Kernel/EntityDisplayTest.php
@@ -29,7 +29,7 @@ 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 09d2a20..78e430c 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/FileFieldFormatterAccessTest.php b/core/modules/file/src/Tests/FileFieldFormatterAccessTest.php
index 68bb047..630fcc9 100644
--- a/core/modules/file/src/Tests/FileFieldFormatterAccessTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/FileFieldRSSContentTest.php b/core/modules/file/src/Tests/FileFieldRSSContentTest.php
index af2b5f2..fcc50b8 100644
--- a/core/modules/file/src/Tests/FileFieldRSSContentTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/FileFieldTestBase.php b/core/modules/file/src/Tests/FileFieldTestBase.php
index b7b90d7..04d4b80 100644
--- a/core/modules/file/src/Tests/FileFieldTestBase.php
+++ b/core/modules/file/src/Tests/FileFieldTestBase.php
@@ -21,7 +21,7 @@
   *
   * @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 ad47d77..263964a 100644
--- a/core/modules/file/src/Tests/FileFieldWidgetTest.php
+++ b/core/modules/file/src/Tests/FileFieldWidgetTest.php
@@ -38,7 +38,7 @@ 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/FileListingTest.php b/core/modules/file/src/Tests/FileListingTest.php
index cca21c5..8b503c6 100644
--- a/core/modules/file/src/Tests/FileListingTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/FileManagedTestBase.php b/core/modules/file/src/Tests/FileManagedTestBase.php
index 879e1c4..0f0ce41 100644
--- a/core/modules/file/src/Tests/FileManagedTestBase.php
+++ b/core/modules/file/src/Tests/FileManagedTestBase.php
@@ -20,7 +20,7 @@
    *
    * @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/src/Tests/FileOnTranslatedEntityTest.php b/core/modules/file/src/Tests/FileOnTranslatedEntityTest.php
index b8a22ae..074dbbf 100644
--- a/core/modules/file/src/Tests/FileOnTranslatedEntityTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/FilePrivateTest.php b/core/modules/file/src/Tests/FilePrivateTest.php
index 0174a89..b89b8d6 100644
--- a/core/modules/file/src/Tests/FilePrivateTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/PrivateFileOnTranslatedEntityTest.php b/core/modules/file/src/Tests/PrivateFileOnTranslatedEntityTest.php
index da5abb5..40249df 100644
--- a/core/modules/file/src/Tests/PrivateFileOnTranslatedEntityTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/RemoteFileSaveUploadTest.php b/core/modules/file/src/Tests/RemoteFileSaveUploadTest.php
index d468ed3..7f28211 100644
--- a/core/modules/file/src/Tests/RemoteFileSaveUploadTest.php
+++ b/core/modules/file/src/Tests/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/src/Tests/SaveUploadFormTest.php b/core/modules/file/src/Tests/SaveUploadFormTest.php
index 6d51198..6603168 100644
--- a/core/modules/file/src/Tests/SaveUploadFormTest.php
+++ b/core/modules/file/src/Tests/SaveUploadFormTest.php
@@ -18,7 +18,7 @@ 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/src/Tests/SaveUploadTest.php b/core/modules/file/src/Tests/SaveUploadTest.php
index a9f69c2..0cd51c9 100644
--- a/core/modules/file/src/Tests/SaveUploadTest.php
+++ b/core/modules/file/src/Tests/SaveUploadTest.php
@@ -15,7 +15,7 @@ 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/src/Tests/Views/RelationshipUserFileDataTest.php b/core/modules/file/src/Tests/Views/RelationshipUserFileDataTest.php
index 6a5f53b..e320f13 100644
--- a/core/modules/file/src/Tests/Views/RelationshipUserFileDataTest.php
+++ b/core/modules/file/src/Tests/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/Functional/FileFieldTestBase.php b/core/modules/file/tests/src/Functional/FileFieldTestBase.php
index d609687..c4a8d3b 100644
--- a/core/modules/file/tests/src/Functional/FileFieldTestBase.php
+++ b/core/modules/file/tests/src/Functional/FileFieldTestBase.php
@@ -18,7 +18,7 @@
   *
   * @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/FileManagedTestBase.php b/core/modules/file/tests/src/Functional/FileManagedTestBase.php
index e0da7d1..a15e666 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/Kernel/AccessTest.php b/core/modules/file/tests/src/Kernel/AccessTest.php
index cfd8e56..5ca2aaa 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 8219af1..345532e 100644
--- a/core/modules/file/tests/src/Kernel/FileItemTest.php
+++ b/core/modules/file/tests/src/Kernel/FileItemTest.php
@@ -23,7 +23,7 @@ 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 c9a247b..f065e8c 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 7c43e9b..d2952b4 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 743da80..a9234cb 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 2965086..9864ef9 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 200dc86..33e813d 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 36e9f1d..a3cc6e5 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 9ea8cce..dd01b69 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 84bd4eb..9bd3449 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 fc379e5..e61aea6 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 = ['menu_ui'];
+  protected static $modules = ['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 88d7c79..3052d1c 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
@@ -15,7 +15,7 @@ class MigrateFileTest extends MigrateDrupal7TestBase {
 
   use FileMigrationSetupTrait;
 
-  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 7b6f763..22a0e65 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 cc8c9b3..4b6ac3d 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 711b36f..e2d34b4 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 96389d5..6803be7 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 8ae0ec4..425a0d3 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 867ab7a..ffed1ed 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 18a6f51..d714bff 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 a6e4293..8053be1 100644
--- a/core/modules/filter/tests/src/Functional/FilterAdminTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterAdminTest.php
@@ -21,7 +21,7 @@ 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 f5423e7..1f05c7f 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 45c3711..bf2832d 100644
--- a/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterDefaultFormatTest.php
@@ -18,7 +18,7 @@ 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 8c3394b..827caf2 100644
--- a/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterFormatAccessTest.php
@@ -20,7 +20,7 @@ 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 5ff4a8a..6a0081b 100644
--- a/core/modules/filter/tests/src/Functional/FilterHooksTest.php
+++ b/core/modules/filter/tests/src/Functional/FilterHooksTest.php
@@ -18,7 +18,7 @@ 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 065d4a6..36c79ee 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 19c57ac..f81ff22 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 4a5b7c4..8ffbced 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/Kernel/FilterAPITest.php b/core/modules/filter/tests/src/Kernel/FilterAPITest.php
index f74edbb..d221056 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 b73b180..b544bcb 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 e16bdda..57e5ea5 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 7b0c029..be1c403 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 f77efac..047d7d6 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 0f54245..ac66176 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 e58861d..7d27269 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 1206734..25cdd98 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 a3e708b..18448d1 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 2dc9ce7..d2a2d48 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 8fca62e..d4c8ed7 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 2914e94..cc1af6f 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 e3d904d..92e293a 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 fb9da66..fceeb60 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 9ba4be7..8aeb722 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 c2d3848..8b6bd4b 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 19c0000..c5d5f65 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 9b9661b..2bbac72 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 302c3d1..2bbc742 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 6f5d48c..d71441c 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 cd1c7fc..891f3ae 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/Functional/EntityResource/Action/ActionHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonAnonTest.php
index 0eae866..55d78fe 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Action/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/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonBasicAuthTest.php
index 5a43a5d..7dcbdab 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Action/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/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonCookieTest.php
index 21f08c5..583400d 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Action/ActionHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Action/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/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonAnonTest.php
index 552437a..8fa1ce0 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class BaseFieldOverrideHalJsonAnonTest extends BaseFieldOverrideResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonBasicAuthTest.php
index ba2249e..92aee8f 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/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/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonCookieTest.php
index b05f153..cd771a4 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class BaseFieldOverrideHalJsonCookieTest extends BaseFieldOverrideResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonAnonTest.php
index d0563c0..bb3cc22 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Block/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/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonBasicAuthTest.php
index 53bcd3e..0230b9b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Block/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/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonCookieTest.php
index 494bb4f..ef5c2f8 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Block/BlockHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Block/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/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonAnonTest.php
index d4ee9ab..6e477d9 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/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/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonBasicAuthTest.php
index 94d3ff4..58d8303 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/BlockContentHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BlockContent/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/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonAnonTest.php
index 006f8fb..bbfde79 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/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/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonBasicAuthTest.php
index 7d392cc..8f5fb27 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/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/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonCookieTest.php
index 565bcf3..ee5a4db 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/BlockContentType/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/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonBasicAuthTest.php
index 7e2dc57..051aca5 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Comment/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/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonTestBase.php b/core/modules/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonTestBase.php
index fc9248a..ffb628a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonTestBase.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Comment/CommentHalJsonTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonAnonTest.php
index 37cf717..8051650 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/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/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonBasicAuthTest.php
index 62b48af..0c0f119 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/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/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonCookieTest.php
index 4a2913b..db42ef4 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/CommentType/CommentTypeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/CommentType/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/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonAnonTest.php
index dbe2a3d..c615fed 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/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/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonBasicAuthTest.php
index 99345ed..4ec3771 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/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/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonCookieTest.php
index d892abf..ca7e7af 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/ConfigTestHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigTest/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/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonAnonTest.php
index 4152a5f..96994e2 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/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/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonBasicAuthTest.php
index 71b41bc..e5a6b90 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/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/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonCookieTest.php
index 357adc0..09da781 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ConfigurableLanguage/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/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php
index 57d6177..40186c2 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/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/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php
index 9aec186..8a426f7 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/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/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php
index 0d78991..14ddba5 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/ContactFormHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContactForm/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/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonAnonTest.php
index e90485d..3339084 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/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/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonBasicAuthTest.php
index 942901b..3cac8e9 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/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/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonCookieTest.php
index 4cc572f..edfb2a6 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ContentLanguageSettings/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/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonAnonTest.php
index 1bd6eb8..954d4b1 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class DateFormatHalJsonAnonTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonBasicAuthTest.php
index 2627c99..62a2fb1 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/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/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonCookieTest.php
index 2367d6c..3df03ec 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/DateFormat/DateFormatHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class DateFormatHalJsonCookieTest extends DateFormatResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonAnonTest.php
index 9b68c54..bc450b3 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Editor/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/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonBasicAuthTest.php
index 9a317a5..09003f7 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Editor/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/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonCookieTest.php
index a59392f..9f8ad6a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Editor/EditorHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Editor/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/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonAnonTest.php
index 199d0c2..417bf8a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityFormDisplayHalJsonAnonTest extends EntityFormDisplayResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonBasicAuthTest.php
index 7e1bc51..66686d7 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/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/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonCookieTest.php
index 5c62956..97e7b1e 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityFormDisplayHalJsonCookieTest extends EntityFormDisplayResourceTestBa
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonAnonTest.php
index 3e99823..8d0bf80 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityFormModeHalJsonAnonTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonBasicAuthTest.php
index 56d4525..b1427de 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/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/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonCookieTest.php
index a84bf6d..df5eada 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityFormModeHalJsonCookieTest extends EntityFormModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonAnonTest.php
index ef3826b..5afdb58 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonAnonTest.php
@@ -18,7 +18,7 @@ class EntityTestHalJsonAnonTest extends EntityTestResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonBasicAuthTest.php
index 65ad0db..97a291b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/EntityTestHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTest/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/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php
index 9e6bcb3..d0f06fe 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/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/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php
index 09e5970..400b48a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/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/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php
index 7f499fa..76ea300 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestBundle/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/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonAnonTest.php
index f95ea5c..2acb760 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/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/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonBasicAuthTest.php
index b3824aa..0cc915b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityTestLabel/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/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonAnonTest.php
index 6fbebad..6f53782 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityViewDisplayHalJsonAnonTest extends EntityViewDisplayResourceTestBase
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonBasicAuthTest.php
index 2c894f7..3547c19 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewDisplay/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/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonAnonTest.php
index d1d4a74..1a82057 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonAnonTest.php
@@ -15,7 +15,7 @@ class EntityViewModeHalJsonAnonTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonBasicAuthTest.php
index a79c3fd..3185bf0 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/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/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonCookieTest.php
index 493de9a..6100866 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeHalJsonCookieTest.php
@@ -15,7 +15,7 @@ class EntityViewModeHalJsonCookieTest extends EntityViewModeResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonBasicAuthTest.php
index c3f91a7..9ef87ed 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Feed/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/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonTestBase.php b/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonTestBase.php
index 4318132..a5cf735 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonTestBase.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Feed/FeedHalJsonTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonAnonTest.php
index 54a418a..c1320d4 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/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/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonBasicAuthTest.php
index 74b60aa..6263e8a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/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/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonCookieTest.php
index e6491f4..88d0f29 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/FieldConfigHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldConfig/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/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonAnonTest.php
index 1b90193..cd790ee 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/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/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonBasicAuthTest.php
index 957e73b..f274213 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/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/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonCookieTest.php
index 20d47a7..278e7c8 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FieldStorageConfig/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/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonAnonTest.php
index b0d1a61..9ddb8d7 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/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/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonBasicAuthTest.php
index fa40970..ede2202 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/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/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonCookieTest.php
index 1957793..4bda6f6 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/FilterFormatHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/FilterFormat/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/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonAnonTest.php
index 34cfd4b..97af7c1 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/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/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonBasicAuthTest.php
index 61cc149..a42e72c 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/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/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonCookieTest.php
index aa49653..df4d9a0 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/ImageStyleHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ImageStyle/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/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonAnonTest.php
index 6c35159..66bbeb3 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Item/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/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonBasicAuthTest.php
index 2c96fbc..7230d98 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Item/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/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonCookieTest.php
index 9c39918..b19ce97 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Item/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/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonTestBase.php b/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonTestBase.php
index 24157e5..c554ab6 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonTestBase.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Item/ItemHalJsonTestBase.php
@@ -18,7 +18,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonAnonTest.php
index c71b54e..e29fba1 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonAnonTest.php
@@ -19,7 +19,7 @@ class MediaHalJsonAnonTest extends MediaResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonBasicAuthTest.php
index a645cbfb..b6f678f 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Media/MediaHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Media/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/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonAnonTest.php
index 1b83df1..940925f 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/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/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonBasicAuthTest.php
index 20c29f2..3b09782 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/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/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonCookieTest.php
index 8c60485..2d1aeeb 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/MediaType/MediaTypeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/MediaType/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/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonAnonTest.php
index ace7df7..9b6254d 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Menu/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/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonBasicAuthTest.php
index 82242e1..7a106ac 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Menu/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/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonCookieTest.php
index 0c1ff4b..87f93c2 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Menu/MenuHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Menu/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/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonAnonTest.php
index c4c8d94..98c5d42 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/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/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonBasicAuthTest.php
index 3af8362..3e32f39 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/MenuLinkContent/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/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonAnonTest.php
index a9b3ae1..beb1037 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Message/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/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonBasicAuthTest.php
index a24fd6e..9415498 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Message/MessageHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Message/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/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonAnonTest.php
index 7bbe218..06ebe47 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Node/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/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonBasicAuthTest.php
index 6ae1285..247a5b3 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Node/NodeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Node/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/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonAnonTest.php
index 5a46564..cfb8d5c 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/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/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonBasicAuthTest.php
index f1b4bca..a5e3e5d 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/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/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonCookieTest.php
index 0b2f9b2..ed892b3 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/NodeType/NodeTypeHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/NodeType/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/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonAnonTest.php
index c8931d7..4613233 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/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/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonBasicAuthTest.php
index 00bc05d..f334775 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/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/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonCookieTest.php
index 458ec7b..de4da06 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/RdfMappingHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RdfMapping/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/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonAnonTest.php
index bb8b50e..eb477fc 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/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/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonBasicAuthTest.php
index 3ce0c72..40e1e2e 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/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/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonCookieTest.php
index 926de66..f02f714 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ResponsiveImageStyle/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/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonAnonTest.php
index 021812b..4470e2e 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/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/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonBasicAuthTest.php
index 495cc04..9ba977f 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/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/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonCookieTest.php
index 7747b1e..d4eba7b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/RestResourceConfig/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/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonAnonTest.php
index ca39204..16ece66 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Role/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/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonBasicAuthTest.php
index 090f153..a6a3c17 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Role/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/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonCookieTest.php
index a98046a..205dd29 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Role/RoleHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Role/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/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonAnonTest.php
index 28777a4..4e9aeff 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/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/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonBasicAuthTest.php
index bb48bbe..151890a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/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/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonCookieTest.php
index 772a4be..fe32a2b 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/SearchPageHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/SearchPage/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/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonAnonTest.php
index c9e8dc0..a8cc32a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/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/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonBasicAuthTest.php
index a5be6db..6d2eb97 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/ShortcutHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Shortcut/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/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonAnonTest.php
index a1cdf27..22ea044 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/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/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonBasicAuthTest.php
index d6cce1d..3cff135 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/ShortcutSet/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/hal/tests/src/Functional/EntityResource/Term/TermHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonAnonTest.php
index 73a1549..73c5216 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonAnonTest.php
@@ -17,7 +17,7 @@ class TermHalJsonAnonTest extends TermResourceTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonBasicAuthTest.php
index 5863338..8c1ef53 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Term/TermHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Term/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/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonAnonTest.php
index 536d634..ad4566c 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Tour/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/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonBasicAuthTest.php
index 07462f1..70e5fd9 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Tour/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/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonCookieTest.php
index cf1b447..1e43aa3 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Tour/TourHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Tour/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/hal/tests/src/Functional/EntityResource/User/UserHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/User/UserHalJsonAnonTest.php
index 7398f28..b2947d2 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/User/UserHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/User/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/hal/tests/src/Functional/EntityResource/User/UserHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/User/UserHalJsonBasicAuthTest.php
index 985b24c..ecc19b7 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/User/UserHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/User/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/hal/tests/src/Functional/EntityResource/View/ViewHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonAnonTest.php
index 432bd3f..530f832 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/View/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/hal/tests/src/Functional/EntityResource/View/ViewHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonBasicAuthTest.php
index 1c5ffc2..dc8b74d 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/View/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/hal/tests/src/Functional/EntityResource/View/ViewHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonCookieTest.php
index e6b3cbe..ddcbb1d 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/View/ViewHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/View/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/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonAnonTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonAnonTest.php
index d4f4bcf..685251a 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonAnonTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/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/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonBasicAuthTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonBasicAuthTest.php
index d53b836..bfdd2bc 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonBasicAuthTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/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/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonCookieTest.php b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonCookieTest.php
index dd37532..5c16afe 100644
--- a/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/VocabularyHalJsonCookieTest.php
+++ b/core/modules/hal/tests/src/Functional/EntityResource/Vocabulary/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/hal/tests/src/Functional/FileDenormalizeTest.php b/core/modules/hal/tests/src/Functional/FileDenormalizeTest.php
index 05ee234..9727ae8 100644
--- a/core/modules/hal/tests/src/Functional/FileDenormalizeTest.php
+++ b/core/modules/hal/tests/src/Functional/FileDenormalizeTest.php
@@ -18,7 +18,7 @@ class FileDenormalizeTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['hal', 'file', 'node'];
+  protected static $modules = ['hal', 'file', 'node'];
 
   /**
    * Tests file entity denormalization.
diff --git a/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php b/core/modules/hal/tests/src/Kernel/EntityTranslationNormalizeTest.php
index 2597af4..d8df345 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 c4b67f5..03c9759 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 def2789..d49aaca 100644
--- a/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php
+++ b/core/modules/hal/tests/src/Kernel/HalLinkManagerTest.php
@@ -17,7 +17,7 @@ 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 ef51a07..5eaa671 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 0eabbda..b30d72f 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 81c4fc1..0354dc6 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 e70eeb7..0ec95c4 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 acb2563..0d7a5d6 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 070a954..542100e 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 065b9af..57b61d3 100644
--- a/core/modules/history/tests/src/Functional/HistoryTest.php
+++ b/core/modules/history/tests/src/Functional/HistoryTest.php
@@ -22,7 +22,7 @@ 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 b9d345e..24778db 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/FileMoveTest.php b/core/modules/image/src/Tests/FileMoveTest.php
index d9ce27f..bb3761d 100644
--- a/core/modules/image/src/Tests/FileMoveTest.php
+++ b/core/modules/image/src/Tests/FileMoveTest.php
@@ -18,7 +18,7 @@ class FileMoveTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * Tests moving a randomly generated image.
diff --git a/core/modules/image/src/Tests/ImageDimensionsTest.php b/core/modules/image/src/Tests/ImageDimensionsTest.php
index b3e100d..95fda37 100644
--- a/core/modules/image/src/Tests/ImageDimensionsTest.php
+++ b/core/modules/image/src/Tests/ImageDimensionsTest.php
@@ -17,7 +17,7 @@ class ImageDimensionsTest extends WebTestBase {
    *
    * @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/src/Tests/ImageFieldDefaultImagesTest.php b/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
index 6255e41..596e77c 100644
--- a/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
+++ b/core/modules/image/src/Tests/ImageFieldDefaultImagesTest.php
@@ -20,7 +20,7 @@ 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/src/Tests/ImageFieldDisplayTest.php b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
index 8061526..1d59277 100644
--- a/core/modules/image/src/Tests/ImageFieldDisplayTest.php
+++ b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
@@ -21,7 +21,7 @@ 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/src/Tests/ImageFieldTestBase.php b/core/modules/image/src/Tests/ImageFieldTestBase.php
index c023917..8880a72 100644
--- a/core/modules/image/src/Tests/ImageFieldTestBase.php
+++ b/core/modules/image/src/Tests/ImageFieldTestBase.php
@@ -33,7 +33,7 @@
    *
    * @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/src/Tests/ImageOnTranslatedEntityTest.php b/core/modules/image/src/Tests/ImageOnTranslatedEntityTest.php
index c5f16cf..5f91d2d 100644
--- a/core/modules/image/src/Tests/ImageOnTranslatedEntityTest.php
+++ b/core/modules/image/src/Tests/ImageOnTranslatedEntityTest.php
@@ -14,7 +14,7 @@ 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/src/Tests/ImageStylesPathAndUrlTest.php b/core/modules/image/src/Tests/ImageStylesPathAndUrlTest.php
index baa4e7f..d7497f8 100644
--- a/core/modules/image/src/Tests/ImageStylesPathAndUrlTest.php
+++ b/core/modules/image/src/Tests/ImageStylesPathAndUrlTest.php
@@ -17,7 +17,7 @@ class ImageStylesPathAndUrlTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'image_module_test'];
+  protected static $modules = ['image', 'image_module_test'];
 
   /**
    * @var \Drupal\image\ImageStyleInterface
diff --git a/core/modules/image/src/Tests/ImageThemeFunctionTest.php b/core/modules/image/src/Tests/ImageThemeFunctionTest.php
index 54c5c64..2d2dbc5 100644
--- a/core/modules/image/src/Tests/ImageThemeFunctionTest.php
+++ b/core/modules/image/src/Tests/ImageThemeFunctionTest.php
@@ -23,7 +23,7 @@ class ImageThemeFunctionTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'entity_test'];
+  protected static $modules = ['image', 'entity_test'];
 
   /**
    * Created file entity.
diff --git a/core/modules/image/src/Tests/QuickEditImageControllerTest.php b/core/modules/image/src/Tests/QuickEditImageControllerTest.php
index cfe4ccb..70bf183 100644
--- a/core/modules/image/src/Tests/QuickEditImageControllerTest.php
+++ b/core/modules/image/src/Tests/QuickEditImageControllerTest.php
@@ -17,7 +17,7 @@ class QuickEditImageControllerTest extends WebTestBase {
   /**
    * {@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/src/Tests/Views/RelationshipUserImageDataTest.php b/core/modules/image/src/Tests/Views/RelationshipUserImageDataTest.php
index 55cecc0..6f12eed 100644
--- a/core/modules/image/src/Tests/Views/RelationshipUserImageDataTest.php
+++ b/core/modules/image/src/Tests/Views/RelationshipUserImageDataTest.php
@@ -21,7 +21,7 @@ class RelationshipUserImageDataTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $modules = ['image', 'image_test_views', 'user'];
+  protected static $modules = ['image', 'image_test_views', 'user'];
 
   /**
    * Views used by this test.
diff --git a/core/modules/image/tests/src/Functional/ImageEffectsTest.php b/core/modules/image/tests/src/Functional/ImageEffectsTest.php
index 3207442..c3bc706 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/ImageFieldTestBase.php b/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
index 5fa0614..c5a1a59 100644
--- a/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
+++ b/core/modules/image/tests/src/Functional/ImageFieldTestBase.php
@@ -30,7 +30,7 @@
    *
    * @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/FunctionalJavascript/QuickEditImageTest.php b/core/modules/image/tests/src/FunctionalJavascript/QuickEditImageTest.php
index 12e43e7..ae73939 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 JavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'image', 'field_ui', 'contextual', 'quickedit', 'toolbar'];
+  protected static $modules = ['node', 'image', 'field_ui', 'contextual', 'quickedit', 'toolbar'];
 
   /**
    * 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 e994f12..c390dfe 100644
--- a/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
@@ -23,7 +23,7 @@ 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 14eeaa3..6ee7fa4 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 951d190..1fa327a 100644
--- a/core/modules/image/tests/src/Kernel/ImageItemTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageItemTest.php
@@ -24,7 +24,7 @@ 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 6a45a98..89a82c4 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 e471c99..09c9247 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/Migrate/d7/MigrateImageSettingsTest.php b/core/modules/image/tests/src/Kernel/Migrate/d7/MigrateImageSettingsTest.php
index b95f0a2..bb8ee2c 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 534a412..fba802a 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 edd2ad3..37abd1c 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 55251d1..198e3af 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 a324d5e..910661b 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/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php b/core/modules/inline_form_errors/tests/src/Functional/FormErrorHandlerFileUploadTest.php
index 9535c99..ef160d1 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 2007e1e..6ac8c9e 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 JavascriptTestBase {
   /**
    * {@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 b956ccc..1aee36d 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 JavascriptTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'quickedit',
     'node',
     'inline_form_errors',
diff --git a/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php b/core/modules/language/tests/src/Functional/AdminPathEntityConverterLanguageTest.php
index f689a92..034e7ab 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 f7b6191..12739f4 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/LanguageBlockSettingsVisibilityTest.php b/core/modules/language/tests/src/Functional/LanguageBlockSettingsVisibilityTest.php
index 003c5a6..5456402 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 e15fcf7..7afa365 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 a63ff45..713f23a 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 2ddd496..956ded1 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 e19fe53..b029b7f 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 87ad05b..c6ad5a5 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 9ed7abd..45d48e0 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 a0510be..152eb51 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 013d00d..b419e19 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 8c671cf..0c6606e 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 a39a112..4201ab5 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 27785c0..81797fe 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 9133a12..6566a97 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 07ae85d..07f7521 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 17ff3f9..a5d663b 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 3d027c3..a8bb900 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 1303082..0ec4fcc 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 13b29f2..c8cba54 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 34f0c81..49ae232 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 7021aa0..5a36c73 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 9a2702d..ef9b021 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/Kernel/Condition/LanguageConditionTest.php b/core/modules/language/tests/src/Kernel/Condition/LanguageConditionTest.php
index af7eed4..f539056 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 92ab889..fecdfa4 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 00af14c..1a717dd 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 88abdd9..97a9616 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 fb62f48..a02334b 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 3082697..722fcbc 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 7d505ba..2b12b54 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 f4dcbd2..458eeae 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 290160c..a5dbe78 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/MigrateLanguageContentSettingsTest.php b/core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageContentSettingsTest.php
index 546ab25..82e6ba8 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 4a88427..d5acb9f 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 ac7ca2e..faea635 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 d7a4551..d9fe6e8 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 09681de..9eae579 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 6aa318e..d04b57a 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 a4c7534..f4fa2da 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 39d6450..3fc1df5 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 cab6fc8..fc4cabf 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_discovery/tests/src/Kernel/LayoutTest.php b/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
index c047850..092a653 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 80913ec..482b42a 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 c99ad0a..6f00d47 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 = ['entity_test', 'link', 'node'];
+  protected static $modules = ['entity_test', 'link', 'node'];
 
   /**
    * A field to use in this test class.
diff --git a/core/modules/link/tests/src/Functional/LinkFieldUITest.php b/core/modules/link/tests/src/Functional/LinkFieldUITest.php
index 0da3938..dfaa5bd 100644
--- a/core/modules/link/tests/src/Functional/LinkFieldUITest.php
+++ b/core/modules/link/tests/src/Functional/LinkFieldUITest.php
@@ -21,7 +21,7 @@ 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/LinkItemTest.php b/core/modules/link/tests/src/Kernel/LinkItemTest.php
index ff4f840..51a6cc3 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 67c2dfa..f83ab31 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'];
 
   /**
    * Test update changes configuration translations if enabled after language.
diff --git a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
index beae85d..22f8e54 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 e795550..51305bd 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 05621f6..4df30eb 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 face32e..66d78e6 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 581c98f..d2c99bc 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 d46fa5e..c542434 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 5425fc5..f18ec5d 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 5f3e5f7..8ea9963 100644
--- a/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleLocaleLookupTest.php
@@ -17,7 +17,7 @@ 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 16cc268..041f7b0 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 57916ca..51bb5aa 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 601b738..0f662cd 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 ffd5bc7..e288053 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 39d7c3d..2f5e48f 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 e7d28b3..d14c9a3 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 f4c59b2..3b08ebc 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 5c972d1..00b86a3 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 c6c69c2..abe14cc 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateInterfaceTest.php
@@ -17,7 +17,7 @@ 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 8389b6e..55e656e 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 3a12efd..1de3128 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 07909ba..0b25752 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/LocaleStringIsSafeTest.php b/core/modules/locale/tests/src/Kernel/LocaleStringIsSafeTest.php
index 4129cdc..5cc4cde 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 370c014..054448d 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 b444918..4327fe3 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/MediaCacheTagsTest.php b/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
index 8da814b..da0597c 100644
--- a/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
+++ b/core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
@@ -18,7 +18,7 @@ class MediaCacheTagsTest extends EntityWithUriCacheTagsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'media',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php b/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
index 017e725..194df6d 100644
--- a/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
+++ b/core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
@@ -17,7 +17,7 @@
    *
    * @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 d13c3f0..307f2ce 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 e0e5294..3de88e9 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 4aa3f00..4bd98d4 100644
--- a/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php
+++ b/core/modules/media/tests/src/Functional/MediaUiFunctionalTest.php
@@ -16,7 +16,7 @@ class MediaUiFunctionalTest extends MediaFunctionalTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'block',
     'media_test_source',
   ];
diff --git a/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php b/core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php
index 7fc26ec..3cba78f 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/MediaUiJavascriptTest.php b/core/modules/media/tests/src/FunctionalJavascript/MediaUiJavascriptTest.php
index 4854a5f..643a74d 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 fa39962..0db265d 100644
--- a/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
+++ b/core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
@@ -20,7 +20,7 @@
    *
    * @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 009e7c4..8976027 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/LinksTest.php b/core/modules/menu_link_content/tests/src/Functional/LinksTest.php
index 6a3d50b..4d8daa1 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 cb1e10d..f5a8ba6 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 464b86c..93b79b4 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 a2ba993..7426d3c 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/Kernel/MenuLinkContentCacheabilityBubblingTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentCacheabilityBubblingTest.php
index c7689d9..e0e0757 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/MenuLinkContentDeriverTest.php b/core/modules/menu_link_content/tests/src/Kernel/MenuLinkContentDeriverTest.php
index 12d8d35..cbb0ba3 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 2c348cf..2cad189 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 f1368ed..b382671 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
@@ -15,7 +15,7 @@ class MigrateMenuLinkTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['menu_ui', 'menu_link_content'];
+  protected static $modules = ['menu_ui', 'menu_link_content'];
 
   /**
    * {@inheritdoc}
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 a5e8dd0..10dee1f 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
@@ -19,7 +19,7 @@ class MigrateMenuLinkTest extends MigrateDrupal7TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['link', 'menu_ui', 'menu_link_content', 'node'];
+  protected static $modules = ['link', 'menu_ui', 'menu_link_content', 'node'];
 
   /**
    * {@inheritdoc}
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 046deb4..ff77b1f 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/source/MenuLinkTest.php b/core/modules/menu_link_content/tests/src/Kernel/Plugin/migrate/source/MenuLinkTest.php
index 7fb3a91..907a9da 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_ui/src/Tests/MenuLanguageTest.php b/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
index 4c48f05..9449a36 100644
--- a/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
@@ -21,7 +21,7 @@ class MenuLanguageTest extends MenuWebTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/menu_ui/src/Tests/MenuNodeTest.php b/core/modules/menu_ui/src/Tests/MenuNodeTest.php
index 9990095..a877943 100644
--- a/core/modules/menu_ui/src/Tests/MenuNodeTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuNodeTest.php
@@ -26,7 +26,7 @@ class MenuNodeTest extends WebTestBase {
    *
    * @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/src/Tests/MenuTest.php b/core/modules/menu_ui/src/Tests/MenuTest.php
index dde9502..8061be7 100644
--- a/core/modules/menu_ui/src/Tests/MenuTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuTest.php
@@ -25,7 +25,7 @@ class MenuTest extends MenuWebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'block', 'contextual', 'help', 'path', 'test_page_test'];
+  protected static $modules = ['node', 'block', 'contextual', 'help', 'path', 'test_page_test'];
 
   /**
    * A user with administration rights.
diff --git a/core/modules/menu_ui/src/Tests/MenuWebTestBase.php b/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
index e0ee98f..628607b 100644
--- a/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
+++ b/core/modules/menu_ui/src/Tests/MenuWebTestBase.php
@@ -14,7 +14,7 @@
    *
    * @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 0b08ebd..bb0ef1b 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 4d2bba6..d794808 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 be018f4..f0a4185 100644
--- a/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php
+++ b/core/modules/menu_ui/tests/src/Functional/MenuUiContentModerationTest.php
@@ -17,7 +17,7 @@ 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/MenuUninstallTest.php b/core/modules/menu_ui/tests/src/Functional/MenuUninstallTest.php
index a0320f4..5fea50f 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 f87bc5f..a311160 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 ccbebff..ae9dc07 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 4198579..d8d7c19 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 faffb66..daf4c62 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 780cce8..55b7b24 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 14e50b9..bd5ae4b 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 019ac42..0f02bcd 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 e2f02ae..ec25676 100644
--- a/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php
+++ b/core/modules/migrate/tests/src/Kernel/MigrateEntityContentBaseTest.php
@@ -23,7 +23,7 @@ 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 8dc4aa9..bd94e30 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 d9728f5..8f87baf 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 207af4d..d451d05 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 3301336..ad08904 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 a639959..8260122 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 427f5bc..de0f04e 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 8c5e01e..4a7a3e8 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 00f07a9..7150f5d 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 51e61d4..e44bdb9 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 5fe56ec..72b5b24 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 dcd070c..242f54c 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/LogTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/LogTest.php
index bb5d04d..85b1256 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/MigrationPluginConfigurationTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginConfigurationTest.php
index 827af91..0f789bb 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 62f3d19..dc8a71b 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationPluginListTest.php
@@ -19,7 +19,7 @@ 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/MigrationProvidersExistTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
index 8e16699..dab8fe5 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
@@ -18,7 +18,7 @@ class MigrationProvidersExistTest extends MigrateDrupalTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['migration_provider_test'];
+  protected static $modules = ['migration_provider_test'];
 
   /**
    * Tests that modules exist for all source and destination plugins.
diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
index 0af1445..19f98e4 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationTest.php
@@ -15,7 +15,7 @@ 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 2b749dc..e074691 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 576539e..eac8e70 100644
--- a/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php
@@ -21,7 +21,7 @@ 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 9338b9e..8dc73f4 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 644371e..f3500c6 100644
--- a/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php
+++ b/core/modules/migrate/tests/src/Kernel/process/FileCopyTest.php
@@ -22,7 +22,7 @@ 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 dc63de3..caae69d 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 3f21235..0d1c687 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 bb314b4..6da76b8 100644
--- a/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/CckFieldBackwardsCompatibilityTest.php
@@ -13,7 +13,7 @@ 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 7eb68ba..cbcd929 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 063c99c..e091b1c 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 7e36364e..d52b92c 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', 'text', 'link', 'migrate_field_plugin_manager_test'];
+  protected static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', '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/VariableMultiRowTest.php b/core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/VariableMultiRowTest.php
index 932af99..bf72ed1 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 b68c4b4..71a80a7 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 8c3e604..8a163cd 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 20b8095..3b4ccd4 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 6be7801..597a4fd 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/MigrateDrupal6TestBase.php b/core/modules/migrate_drupal/tests/src/Kernel/d6/MigrateDrupal6TestBase.php
index 3a9467e..e7dcd86 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/dependencies/MigrateDependenciesTest.php b/core/modules/migrate_drupal/tests/src/Kernel/dependencies/MigrateDependenciesTest.php
index 1a30489..9719872 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 f785a57..4f6b8be 100644
--- a/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/src/Tests/MigrateUpgradeTestBase.php
@@ -35,7 +35,7 @@
    *
    * @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 3c475e2..307f75e 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/MigrateUpgradeTestBase.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
index 0b39b2b..56894c8 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
@@ -30,7 +30,7 @@
    *
    * @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/d7/MigrateUpgrade7Test.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
index f22a9f7..c1903af 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
@@ -17,7 +17,7 @@ class MigrateUpgrade7Test extends MigrateUpgradeTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['file'];
+  protected static $modules = ['file'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/node/src/Tests/NodeRevisionsTest.php b/core/modules/node/src/Tests/NodeRevisionsTest.php
index efb4011..dadb2c8 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 2dcaba5..ede5193 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 70d3ac4..805d1ce 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 ed4c6fa..18e2540 100644
--- a/core/modules/node/src/Tests/PagePreviewTest.php
+++ b/core/modules/node/src/Tests/PagePreviewTest.php
@@ -29,7 +29,7 @@ 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 dc23d0c..38578e3 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 cb765d4..652d3ce 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/Migrate/d6/MigrateNodeRevisionTest.php b/core/modules/node/tests/src/Functional/Migrate/d6/MigrateNodeRevisionTest.php
index 075e727..d0c9607 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 621cdb6..fb9ed7a 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 2015455..6e2a2ae 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 d9e4e8b..cd8040b 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 8028ec9..dbcf30c 100644
--- a/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessFieldTest.php
@@ -18,7 +18,7 @@ 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 fa2116a..0a5da3e 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 e388afc..31a5f35 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 48f9dfa..f041d24 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/NodeAccessLanguageTest.php b/core/modules/node/tests/src/Functional/NodeAccessLanguageTest.php
index 1af5660..5aadddb 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 6c5bcd4..ddefa1c 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 ad6cc54..ef685c6 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 259ed83..853d7f3 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 d026902..9ff6b79 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 24a50cf..9417ba1 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 c203c50..738bc0d 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 ca5a0a9..dd38908 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/NodeCreationTest.php b/core/modules/node/tests/src/Functional/NodeCreationTest.php
index 1ea8fcc..c555fcb 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 c15ca70..be70c15 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 be0f1c0..f2294b7 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 771426d..ba59e03 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 607e68c..7c4fb4b 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 c4b7139..a02aa53 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 7bd725b..0950e14 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 2da5d1b..9db35c2 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/NodeQueryAlterTest.php b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
index 362a27f..1c3503a 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 0efa336..7701560 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 186b694..e120f12 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 6c508ae..f12e612 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 c1daef9..03fe59f 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 2ef0d73..fe30c4e 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 8c94f79..405247f 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 a44bea1..58c0ed8 100644
--- a/core/modules/node/tests/src/Functional/NodeTranslationUITest.php
+++ b/core/modules/node/tests/src/Functional/NodeTranslationUITest.php
@@ -35,7 +35,7 @@ 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 9c442fd..698e14b 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 07e61a0..a85f7fc 100644
--- a/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php
+++ b/core/modules/node/tests/src/Functional/NodeTypeTranslationTest.php
@@ -22,7 +22,7 @@ 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 4730427..205fbbf 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/Views/BulkFormAccessTest.php b/core/modules/node/tests/src/Functional/Views/BulkFormAccessTest.php
index 194b9b0..2784711 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 319890b..e56cd36 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 7eb7097..83976e4 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 37a6b91..69cf143 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 c2ee2f2..cdb0816 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 d2d1b47..b252cfe 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 b98778c..f8a6a3c 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 d8d088d..b37fdf3 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 fdd4d45..5708377 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/TestSettingSummariesContentType.php b/core/modules/node/tests/src/FunctionalJavascript/TestSettingSummariesContentType.php
index 4760ee6..0671c62 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 JavascriptTestBase {
   /**
    * {@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 88eb122..f7d4efb 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 e1b17f2..6518a0c 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 cb98517..dfb80fd 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 5b393b1..d0b66f7 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 9f28c06..9d18801 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 e7eb008..6dd69f2 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 afd2dc6..d59f63f 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 58eeca3..aaf6863 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 ce4ce76..88e8b5c 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 = ['language', 'content_translation', 'menu_ui'];
+  protected static $modules = ['language', 'content_translation', 'menu_ui'];
 
   /**
    * {@inheritdoc}
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 9a3e81e..d43f64c 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 7daac88..eed47eb 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/MigrateNodeSettingsTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeSettingsTest.php
index dcae81b..c0f5de8 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 dc053a8..bf9d6e2 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 0655631..ed5239f 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 b16cd25..130aa9d 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 88cc2ad..a28c8fe 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 539edcb..84a0d52 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 3dd1349..bb60a5c 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 a30867c..15b704e 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 ae66dca..0b43aff 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 7c7bc03..453ccab 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 0a0f145..a39b0a6 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 c12f311..0c00164 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 dd39b6d..50d6ace 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 e111fae..97c598f 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/Plugin/migrate/source/d6/NodeByNodeTypeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d6/NodeByNodeTypeTest.php
index d5a8db0..d35d6fe 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 27e17cc..75434ab 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 fbc28c5..11d63de 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 4bc1be0..9a78d61 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 e7de62b..95addeb 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 9d59f43..bd349c6 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 18d941c..e818cbe 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/NodeTest.php b/core/modules/node/tests/src/Kernel/Plugin/migrate/source/d7/NodeTest.php
index da4f57e..f3b40fd 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 e46bd35..c73f834 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 5e876b7..45f0541 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 fa15c0e..15cdfb4 100644
--- a/core/modules/node/tests/src/Kernel/SummaryLengthTest.php
+++ b/core/modules/node/tests/src/Kernel/SummaryLengthTest.php
@@ -37,7 +37,7 @@ 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 b216f40..8ffb8b3 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 78ec67b..faea637 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 7c68e88..4587d6f 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 287bf48..3c2ffca 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 e47bdd0..3a021bc 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 64e9010..94a86bf 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 ec5874b..c6a1037 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 befd48e..518d12b 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 a2157f1..ea5cb2d 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 401d6bc..6395e87 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 9098b81..121a595 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 c5f2902..ea35b87 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 9f53e63..4f612b6 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 d023598..801cd1e 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 bf4951d..01b9cd5 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 33cf5ab..b42349b 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 a43a1f8..5910aa5 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 a12b282..7a0e09c 100644
--- a/core/modules/path/tests/src/Functional/PathAliasTest.php
+++ b/core/modules/path/tests/src/Functional/PathAliasTest.php
@@ -19,7 +19,7 @@ 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 87f117b..5f81395 100644
--- a/core/modules/path/tests/src/Functional/PathContentModerationTest.php
+++ b/core/modules/path/tests/src/Functional/PathContentModerationTest.php
@@ -19,7 +19,7 @@ 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 8e41ede..2fa6d07 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 c2e3276..c9d235b 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/PathNodeFormTest.php b/core/modules/path/tests/src/Functional/PathNodeFormTest.php
index ea730fd..79ba527 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 80bedab..1730d26 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 d4b8826..e7b9096 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 092d5ac..5396007 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 = ['language', 'content_translation', 'path', 'menu_ui'];
+  protected static $modules = ['language', 'content_translation', 'path', 'menu_ui'];
 
   /**
    * {@inheritdoc}
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 2edf258..acb2610 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 88044c3..bacf9bd 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 602e84f..10fa6a0 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 1057dff..4cfe6d1 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 2fdfd36..191b079 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 a1ef6cd..86fa48b 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 9ca558a..2db1249 100644
--- a/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php
+++ b/core/modules/quickedit/src/Tests/QuickEditLoadingTest.php
@@ -27,7 +27,7 @@ class QuickEditLoadingTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'contextual',
     'quickedit',
     'filter',
diff --git a/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php b/core/modules/quickedit/tests/src/Kernel/MetadataGeneratorTest.php
index 42c4103..7849a01 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 2943748..7e84ed9 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/src/Tests/CommentAttributesTest.php b/core/modules/rdf/src/Tests/CommentAttributesTest.php
index 8ca5798..0b7fc50 100644
--- a/core/modules/rdf/src/Tests/CommentAttributesTest.php
+++ b/core/modules/rdf/src/Tests/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/src/Tests/GetNamespacesTest.php b/core/modules/rdf/src/Tests/GetNamespacesTest.php
index ca46c5c..1f678ff 100644
--- a/core/modules/rdf/src/Tests/GetNamespacesTest.php
+++ b/core/modules/rdf/src/Tests/GetNamespacesTest.php
@@ -17,7 +17,7 @@ class GetNamespacesTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['rdf', 'rdf_test_namespaces'];
+  protected static $modules = ['rdf', 'rdf_test_namespaces'];
 
   /**
    * Tests RDF namespaces.
diff --git a/core/modules/rdf/src/Tests/ImageFieldAttributesTest.php b/core/modules/rdf/src/Tests/ImageFieldAttributesTest.php
index d4d7d35..026126b 100644
--- a/core/modules/rdf/src/Tests/ImageFieldAttributesTest.php
+++ b/core/modules/rdf/src/Tests/ImageFieldAttributesTest.php
@@ -19,7 +19,7 @@ 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/EntityReferenceFieldAttributesTest.php b/core/modules/rdf/tests/src/Functional/EntityReferenceFieldAttributesTest.php
index b91215d..2aa26e2 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 ad74358..ddf82b6 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 5d31d3a..3ce4b45 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/NodeAttributesTest.php b/core/modules/rdf/tests/src/Functional/NodeAttributesTest.php
index 87067bd..af0180b 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/TaxonomyAttributesTest.php b/core/modules/rdf/tests/src/Functional/TaxonomyAttributesTest.php
index 346ffb7..bd9c187 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 7e98286..b0c8a11 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 f8292a3..12a5c3d 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 fc78691..d3d7716 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 85ae888..91696e7 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 9312fbc..e61b5ba 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 94f7f24..3ec663c 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'];
+  protected static $modules = ['text', 'filter'];
 
   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 82ea9ef..5568f83 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 30735e3..f63156a 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 d705b21..d28a319 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 48bc5b8..34ad8cc 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/RdfaAttributesTest.php b/core/modules/rdf/tests/src/Kernel/RdfaAttributesTest.php
index 39f4831..f3f6868 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 b50d71b..ae92eb5 100644
--- a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php
+++ b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldDisplayTest.php
@@ -32,7 +32,7 @@ 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 c879e72..0e2ced2 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/ResponsiveImageAdminUITest.php b/core/modules/responsive_image/tests/src/Functional/ResponsiveImageAdminUITest.php
index eeaf793..668ab28 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/Kernel/ResponsiveImageIntegrationTest.php b/core/modules/responsive_image/tests/src/Kernel/ResponsiveImageIntegrationTest.php
index d481291..00641c6 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 3f97e46..fce925d 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/Action/ActionJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Action/ActionJsonBasicAuthTest.php
index bc998ed..e391dac 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Action/ActionJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Action/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/rest/tests/src/Functional/EntityResource/Action/ActionResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Action/ActionResourceTestBase.php
index 76aff4b..261788a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Action/ActionResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Action/ActionResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideJsonBasicAuthTest.php
index 010fa8d..918d6e7 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/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/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideResourceTestBase.php
index 1f4b03a..449cb20 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BaseFieldOverride/BaseFieldOverrideResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'node'];
+  protected static $modules = ['field', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockJsonBasicAuthTest.php
index ea690b4..c9a1729 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Block/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/rest/tests/src/Functional/EntityResource/Block/BlockResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockResourceTestBase.php
index d86f9b1..e513d9a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Block/BlockResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentJsonBasicAuthTest.php
index c804632..fcc8fbf 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/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/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
index 8b67cc6..2eadf04 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BlockContent/BlockContentResourceTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeJsonBasicAuthTest.php
index e46afdc..20ace61 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/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/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeResourceTestBase.php
index f96f40e..2173b96 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/BlockContentType/BlockContentTypeResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['block_content'];
+  protected static $modules = ['block_content'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentJsonBasicAuthTest.php
index e05d733..69d0a13 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Comment/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/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
index bade2a7..8b9f3c7 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Comment/CommentResourceTestBase.php
@@ -18,7 +18,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'entity_test'];
+  protected static $modules = ['comment', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeJsonBasicAuthTest.php
index b91bad8..c34174f 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/CommentType/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/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeResourceTestBase.php
index 9d88211..672c215 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/CommentType/CommentTypeResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestJsonBasicAuthTest.php
index 1144e76..fb10409 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/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/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestResourceTestBase.php
index 9fe073b..2d609da 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/ConfigTestResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ConfigTest/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/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageJsonBasicAuthTest.php
index e453f95..e57eed6 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/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/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageResourceTestBase.php
index cf5be74..5a2a56a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ConfigurableLanguage/ConfigurableLanguageResourceTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php
index c41b9a4..d54dcf8 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/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/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
index 51e297a..cbad954 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContactForm/ContactFormResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsJsonBasicAuthTest.php
index 392213f..1942d17 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/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/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsResourceTestBase.php
index a8b3f8c..9163073 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ContentLanguageSettings/ContentLanguageSettingsResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language', 'node'];
+  protected static $modules = ['language', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatJsonBasicAuthTest.php
index 71f1f7f..0076ab0 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/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/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatResourceTestBase.php
index 8fce0fe..83e49b6 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/DateFormat/DateFormatResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorJsonBasicAuthTest.php
index 265bd48..2e79426 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Editor/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/rest/tests/src/Functional/EntityResource/Editor/EditorResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorResourceTestBase.php
index 4eb4a6e..231a9e4 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Editor/EditorResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['ckeditor', 'editor'];
+  protected static $modules = ['ckeditor', 'editor'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayJsonBasicAuthTest.php
index 940e73b..2c24427 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/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/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayResourceTestBase.php
index cc4cf58..21756e7 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormDisplay/EntityFormDisplayResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeJsonBasicAuthTest.php
index 989cd5b..3265212 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/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/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeResourceTestBase.php
index a9035e0..2de86de 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/EntityFormModeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityFormMode/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/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
index 41d9eec..23f66ef 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php
@@ -131,7 +131,7 @@
    *
    * @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/EntityResource/EntityTest/EntityTestJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestJsonBasicAuthTest.php
index aff854e..44136d0 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/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/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
index e2c0ccd..90fa3dc 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTest/EntityTestResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php
index 0220801..a902d7c 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/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/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
index f43d877..ee6638b 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestBundle/EntityTestBundleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelJsonBasicAuthTest.php
index 2a43e03..5e28afd 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/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/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
index 2257d6c..298c6d3 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityTestLabel/EntityTestLabelResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['entity_test'];
+  protected static $modules = ['entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayJsonBasicAuthTest.php
index 457c42f..023c494 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/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/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayResourceTestBase.php
index ccc3aad..4822905 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewDisplay/EntityViewDisplayResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeJsonBasicAuthTest.php
index 986b31d..e613498 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/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/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeResourceTestBase.php
index 28cb9b0..e1c22ea 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/EntityViewModeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/EntityViewMode/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/modules/rest/tests/src/Functional/EntityResource/Feed/FeedJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Feed/FeedJsonBasicAuthTest.php
index e5685c9..0937b4d 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Feed/FeedJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Feed/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/rest/tests/src/Functional/EntityResource/Feed/FeedResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Feed/FeedResourceTestBase.php
index 1e79395..6354c4e 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Feed/FeedResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Feed/FeedResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigJsonBasicAuthTest.php
index 2ab43d3..c7cb34d 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/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/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigResourceTestBase.php
index 05c05f4..28b0930 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FieldConfig/FieldConfigResourceTestBase.php
@@ -12,7 +12,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field', 'node'];
+  protected static $modules = ['field', 'node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigJsonBasicAuthTest.php
index 4219cad..26a172e 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/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/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigResourceTestBase.php
index aafc253..d1e9d4d 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FieldStorageConfig/FieldStorageConfigResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatJsonBasicAuthTest.php
index 4e143c3..353eb96 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/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/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatResourceTestBase.php
index 4d65e00..16ba09d 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/FilterFormat/FilterFormatResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleJsonBasicAuthTest.php
index 1011750..8fb8877 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/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/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleResourceTestBase.php
index ccd68d9..af48030 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ImageStyle/ImageStyleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['image'];
+  protected static $modules = ['image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemJsonBasicAuthTest.php
index 19b6179..e3ffba4 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Item/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/rest/tests/src/Functional/EntityResource/Item/ItemResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemResourceTestBase.php
index f217b97..f4c5264 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Item/ItemResourceTestBase.php
@@ -17,7 +17,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['aggregator'];
+  protected static $modules = ['aggregator'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaJsonBasicAuthTest.php
index f499b79..a3bb391 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Media/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/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
index 475a1ca..f5e46ec 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Media/MediaResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeJsonBasicAuthTest.php
index 052b19d..9e5a511 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/MediaType/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/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeResourceTestBase.php
index ac72737..2caf9d2 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/MediaType/MediaTypeResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['media'];
+  protected static $modules = ['media'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuJsonBasicAuthTest.php
index b419eaf..824b039 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Menu/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/rest/tests/src/Functional/EntityResource/Menu/MenuResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuResourceTestBase.php
index dd7f552..747a3b2 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Menu/MenuResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentJsonBasicAuthTest.php
index 952088b..b037bdb 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/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/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentResourceTestBase.php
index 0b1f967..872cffa 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/MenuLinkContentResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/MenuLinkContent/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/rest/tests/src/Functional/EntityResource/Message/MessageJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Message/MessageJsonBasicAuthTest.php
index 1232fb7..d8361eb 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Message/MessageJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Message/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/rest/tests/src/Functional/EntityResource/Message/MessageResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Message/MessageResourceTestBase.php
index 3f1cab9..4bfce39 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Message/MessageResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Message/MessageResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['contact'];
+  protected static $modules = ['contact'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeJsonBasicAuthTest.php
index ff7746d..56530fe 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Node/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/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
index 492ff64..851f6ec 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Node/NodeResourceTestBase.php
@@ -16,7 +16,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'path'];
+  protected static $modules = ['node', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeJsonBasicAuthTest.php
index cee2364..1bb2f0c 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/NodeType/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/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeResourceTestBase.php
index c374bfb..6f49fb2 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/NodeType/NodeTypeResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingJsonBasicAuthTest.php
index 857d8c7..4d5dd45 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/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/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingResourceTestBase.php
index c826be0..ebc1164 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/RdfMapping/RdfMappingResourceTestBase.php
@@ -11,7 +11,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'rdf'];
+  protected static $modules = ['node', 'rdf'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleJsonBasicAuthTest.php
index dbd6e7c..2e88afb 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/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/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleResourceTestBase.php
index 4221314..2177f39 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ResponsiveImageStyle/ResponsiveImageStyleResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['responsive_image'];
+  protected static $modules = ['responsive_image'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigJsonBasicAuthTest.php
index 136474b..0e65d81 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/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/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php
index a19e2ef..f523397 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/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/EntityResource/Role/RoleJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Role/RoleJsonBasicAuthTest.php
index 267a3b8..85483ee 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Role/RoleJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Role/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/rest/tests/src/Functional/EntityResource/Role/RoleResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Role/RoleResourceTestBase.php
index ee719c4..5ecb92f 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Role/RoleResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Role/RoleResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageJsonBasicAuthTest.php
index 0ee5556..0a8e1d1 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/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/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageResourceTestBase.php
index e81993f..c111f73 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/SearchPage/SearchPageResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'search'];
+  protected static $modules = ['node', 'search'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutJsonBasicAuthTest.php
index 31f1117..64a1d8c 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/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/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
index 36be5b5..7b7235f 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Shortcut/ShortcutResourceTestBase.php
@@ -14,7 +14,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['comment', 'shortcut'];
+  protected static $modules = ['comment', 'shortcut'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetJsonBasicAuthTest.php
index 388b9de..8fa4168 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/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/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetResourceTestBase.php
index 97ae1a6..e52a2e7 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/ShortcutSet/ShortcutSetResourceTestBase.php
@@ -13,7 +13,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['shortcut'];
+  protected static $modules = ['shortcut'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Term/TermJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Term/TermJsonBasicAuthTest.php
index 97df5c8..a3fa996 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Term/TermJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Term/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/rest/tests/src/Functional/EntityResource/Term/TermResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Term/TermResourceTestBase.php
index e0a1581..e7c6818 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Term/TermResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Term/TermResourceTestBase.php
@@ -15,7 +15,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy', 'path'];
+  protected static $modules = ['taxonomy', 'path'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourJsonBasicAuthTest.php
index 67d7fd3..6141698 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Tour/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/rest/tests/src/Functional/EntityResource/Tour/TourResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourResourceTestBase.php
index 294e3ee..cd4749c 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Tour/TourResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['tour'];
+  protected static $modules = ['tour'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/User/UserJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/User/UserJsonBasicAuthTest.php
index ea6ddea..2e5637a 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/User/UserJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/User/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/rest/tests/src/Functional/EntityResource/User/UserResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/User/UserResourceTestBase.php
index caf2909..766f638 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/User/UserResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/User/UserResourceTestBase.php
@@ -15,7 +15,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['user'];
+  protected static $modules = ['user'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/View/ViewJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/View/ViewJsonBasicAuthTest.php
index 98854f2..f5d38d5 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/View/ViewJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/View/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/rest/tests/src/Functional/EntityResource/View/ViewResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/View/ViewResourceTestBase.php
index 26ec7bb..1343de3 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/View/ViewResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/View/ViewResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['views'];
+  protected static $modules = ['views'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyJsonBasicAuthTest.php b/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyJsonBasicAuthTest.php
index 492a8ad..4eda380 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyJsonBasicAuthTest.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/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/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyResourceTestBase.php b/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyResourceTestBase.php
index abada74..85c851b 100644
--- a/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyResourceTestBase.php
+++ b/core/modules/rest/tests/src/Functional/EntityResource/Vocabulary/VocabularyResourceTestBase.php
@@ -10,7 +10,7 @@
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/rest/tests/src/Functional/ResourceTest.php b/core/modules/rest/tests/src/Functional/ResourceTest.php
index 1e8babe..33a66c2 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 0a0e34c..e7df35c 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/Views/ExcludedFieldTokenTest.php b/core/modules/rest/tests/src/Functional/Views/ExcludedFieldTokenTest.php
index cf9913d..5eef6fa8 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 2454608..476bfcf 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 94af542..1382767 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 51ad3e9..693b1f5 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 89e9b1d..5857433 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 808d434..6724332 100644
--- a/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
+++ b/core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
@@ -25,7 +25,7 @@ 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 9d32f7f..0f24c6a 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 f3a8f04..04c708c 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 829d08b..029b523 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/SearchBlockTest.php b/core/modules/search/src/Tests/SearchBlockTest.php
index 21afda7..03df03d 100644
--- a/core/modules/search/src/Tests/SearchBlockTest.php
+++ b/core/modules/search/src/Tests/SearchBlockTest.php
@@ -14,7 +14,7 @@ class SearchBlockTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/src/Tests/SearchCommentTest.php b/core/modules/search/src/Tests/SearchCommentTest.php
index 7047429..3945269 100644
--- a/core/modules/search/src/Tests/SearchCommentTest.php
+++ b/core/modules/search/src/Tests/SearchCommentTest.php
@@ -22,7 +22,7 @@ class SearchCommentTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'node', 'comment'];
+  protected static $modules = ['filter', 'node', 'comment'];
 
   /**
    * Test subject for comments.
diff --git a/core/modules/search/src/Tests/SearchConfigSettingsFormTest.php b/core/modules/search/src/Tests/SearchConfigSettingsFormTest.php
index b081b85..d94600c 100644
--- a/core/modules/search/src/Tests/SearchConfigSettingsFormTest.php
+++ b/core/modules/search/src/Tests/SearchConfigSettingsFormTest.php
@@ -17,7 +17,7 @@ class SearchConfigSettingsFormTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'search_extra_type', 'test_page_test'];
+  protected static $modules = ['block', 'search_extra_type', 'test_page_test'];
 
   /**
    * User who can search and administer search.
diff --git a/core/modules/search/src/Tests/SearchEmbedFormTest.php b/core/modules/search/src/Tests/SearchEmbedFormTest.php
index 5f3fbea..49df65c 100644
--- a/core/modules/search/src/Tests/SearchEmbedFormTest.php
+++ b/core/modules/search/src/Tests/SearchEmbedFormTest.php
@@ -14,7 +14,7 @@ class SearchEmbedFormTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['search_embedded_form'];
+  protected static $modules = ['search_embedded_form'];
 
   /**
    * Node used for testing.
diff --git a/core/modules/search/src/Tests/SearchLanguageTest.php b/core/modules/search/src/Tests/SearchLanguageTest.php
index ec15085..202a640 100644
--- a/core/modules/search/src/Tests/SearchLanguageTest.php
+++ b/core/modules/search/src/Tests/SearchLanguageTest.php
@@ -17,7 +17,7 @@ class SearchLanguageTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Array of nodes available to search.
diff --git a/core/modules/search/src/Tests/SearchNodeUpdateAndDeletionTest.php b/core/modules/search/src/Tests/SearchNodeUpdateAndDeletionTest.php
index c19814e..6ae3947 100644
--- a/core/modules/search/src/Tests/SearchNodeUpdateAndDeletionTest.php
+++ b/core/modules/search/src/Tests/SearchNodeUpdateAndDeletionTest.php
@@ -14,7 +14,7 @@ class SearchNodeUpdateAndDeletionTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = [];
+  protected static $modules = [];
 
   /**
    * A user with permission to access and search content.
diff --git a/core/modules/search/src/Tests/SearchPageTextTest.php b/core/modules/search/src/Tests/SearchPageTextTest.php
index 95d097d..0b85c5c 100644
--- a/core/modules/search/src/Tests/SearchPageTextTest.php
+++ b/core/modules/search/src/Tests/SearchPageTextTest.php
@@ -23,7 +23,7 @@ class SearchPageTextTest extends SearchTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/search/src/Tests/SearchPreprocessLangcodeTest.php b/core/modules/search/src/Tests/SearchPreprocessLangcodeTest.php
index ab264a1..e7047de 100644
--- a/core/modules/search/src/Tests/SearchPreprocessLangcodeTest.php
+++ b/core/modules/search/src/Tests/SearchPreprocessLangcodeTest.php
@@ -14,7 +14,7 @@ class SearchPreprocessLangcodeTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['search_langcode_test'];
+  protected static $modules = ['search_langcode_test'];
 
   /**
    * Test node for searching.
diff --git a/core/modules/search/src/Tests/SearchQueryAlterTest.php b/core/modules/search/src/Tests/SearchQueryAlterTest.php
index 66269dd..ff28850 100644
--- a/core/modules/search/src/Tests/SearchQueryAlterTest.php
+++ b/core/modules/search/src/Tests/SearchQueryAlterTest.php
@@ -13,7 +13,7 @@ class SearchQueryAlterTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['search_query_alter'];
+  protected static $modules = ['search_query_alter'];
 
   /**
    * Tests that the query alter works.
diff --git a/core/modules/search/src/Tests/SearchRankingTest.php b/core/modules/search/src/Tests/SearchRankingTest.php
index 55da9ac..420a53f 100644
--- a/core/modules/search/src/Tests/SearchRankingTest.php
+++ b/core/modules/search/src/Tests/SearchRankingTest.php
@@ -29,7 +29,7 @@ class SearchRankingTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['statistics', 'comment'];
+  protected static $modules = ['statistics', 'comment'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/src/Tests/SearchTestBase.php b/core/modules/search/src/Tests/SearchTestBase.php
index 1c157b6..b07f098 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/SearchCommentCountToggleTest.php b/core/modules/search/tests/src/Functional/SearchCommentCountToggleTest.php
index 7cd9f85..76bbd11 100644
--- a/core/modules/search/tests/src/Functional/SearchCommentCountToggleTest.php
+++ b/core/modules/search/tests/src/Functional/SearchCommentCountToggleTest.php
@@ -26,7 +26,7 @@ class SearchCommentCountToggleTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   /**
    * A user with permission to search and post comments.
diff --git a/core/modules/search/tests/src/Functional/SearchDateIntervalTest.php b/core/modules/search/tests/src/Functional/SearchDateIntervalTest.php
index 8276913..46ff50c 100644
--- a/core/modules/search/tests/src/Functional/SearchDateIntervalTest.php
+++ b/core/modules/search/tests/src/Functional/SearchDateIntervalTest.php
@@ -16,7 +16,7 @@ class SearchDateIntervalTest extends SearchTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['language', 'search_date_query_alter'];
+  protected static $modules = ['language', 'search_date_query_alter'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/tests/src/Functional/SearchKeywordsConditionsTest.php b/core/modules/search/tests/src/Functional/SearchKeywordsConditionsTest.php
index 26bff66..8ea5b16 100644
--- a/core/modules/search/tests/src/Functional/SearchKeywordsConditionsTest.php
+++ b/core/modules/search/tests/src/Functional/SearchKeywordsConditionsTest.php
@@ -20,7 +20,7 @@ class SearchKeywordsConditionsTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment', 'search_extra_type', 'test_page_test'];
+  protected static $modules = ['comment', 'search_extra_type', 'test_page_test'];
 
   /**
    * A user with permission to search and post comments.
diff --git a/core/modules/search/tests/src/Functional/SearchMultilingualEntityTest.php b/core/modules/search/tests/src/Functional/SearchMultilingualEntityTest.php
index 9b3a6dd..c658058 100644
--- a/core/modules/search/tests/src/Functional/SearchMultilingualEntityTest.php
+++ b/core/modules/search/tests/src/Functional/SearchMultilingualEntityTest.php
@@ -26,7 +26,7 @@ class SearchMultilingualEntityTest extends SearchTestBase {
    */
   protected $plugin;
 
-  public static $modules = ['language', 'locale', 'comment'];
+  protected static $modules = ['language', 'locale', 'comment'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/search/tests/src/Functional/SearchPageOverrideTest.php b/core/modules/search/tests/src/Functional/SearchPageOverrideTest.php
index 4dfca49..c3077f2 100644
--- a/core/modules/search/tests/src/Functional/SearchPageOverrideTest.php
+++ b/core/modules/search/tests/src/Functional/SearchPageOverrideTest.php
@@ -17,7 +17,7 @@ class SearchPageOverrideTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['search_extra_type'];
+  protected static $modules = ['search_extra_type'];
 
   /**
    * A user with permission to administer search.
diff --git a/core/modules/search/tests/src/Functional/SearchSetLocaleTest.php b/core/modules/search/tests/src/Functional/SearchSetLocaleTest.php
index f6923f4..c8e916d 100644
--- a/core/modules/search/tests/src/Functional/SearchSetLocaleTest.php
+++ b/core/modules/search/tests/src/Functional/SearchSetLocaleTest.php
@@ -14,7 +14,7 @@ class SearchSetLocaleTest extends SearchTestBase {
    *
    * @var array
    */
-  public static $modules = ['comment'];
+  protected static $modules = ['comment'];
 
   /**
    * A node search plugin instance.
diff --git a/core/modules/search/tests/src/Functional/SearchTestBase.php b/core/modules/search/tests/src/Functional/SearchTestBase.php
index 3739b57..1f54fcd 100644
--- a/core/modules/search/tests/src/Functional/SearchTestBase.php
+++ b/core/modules/search/tests/src/Functional/SearchTestBase.php
@@ -15,7 +15,7 @@
    *
    * @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 a70114a..9ca8a97 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 d28bbd8..625a69a 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 86d3b22..fda72cf 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 2306ce7..47f584a 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 e10075d..035bf2d 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 7037646..1cf52e0 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 38af46e..4332d95 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 5b71b93..780757f 100644
--- a/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
+++ b/core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
@@ -20,7 +20,7 @@ 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 3e41d63..d955baf 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/NormalizerTestBase.php b/core/modules/serialization/tests/src/Kernel/NormalizerTestBase.php
index 25299b1..9db09bb 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 a7ad145..b0b6a33 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/SettingsTrayTest.php b/core/modules/settings_tray/tests/src/Functional/SettingsTrayTest.php
index aec0392..e9fadc8 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/SettingsTrayBlockFormTest.php b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
index fcfecde..58e4bb6 100644
--- a/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
+++ b/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php
@@ -27,7 +27,7 @@ class SettingsTrayBlockFormTest extends OffCanvasTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'node',
     'block',
     'system',
diff --git a/core/modules/shortcut/src/Tests/ShortcutTestBase.php b/core/modules/shortcut/src/Tests/ShortcutTestBase.php
index 584a615..ddf192e 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/ShortcutCacheTagsTest.php b/core/modules/shortcut/tests/src/Functional/ShortcutCacheTagsTest.php
index e2d6a22..ccbb213 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 e39f652..65c68ae 100644
--- a/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
+++ b/core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
@@ -25,7 +25,7 @@ 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 b897df7..76da164 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 3f9cc87..94d78fa 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 83bf47a..da9cb95 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 f5b01d9..e52b327 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 b654372..d68c9d8 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 ae93956..b147881 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 e685151..f81cc24 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 e1982de..302f80d 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 035aec3..5dc83f7 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 9f8fd3a..bc4651c 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 0d58c31..2e43bf7 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 7bc20ec..4a26bf1 100644
--- a/core/modules/simpletest/src/KernelTestBase.php
+++ b/core/modules/simpletest/src/KernelTestBase.php
@@ -86,7 +86,7 @@
    *
    * @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 febb9cf..6fb4c31 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 fdfaff8..bbed3de 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 379aed4..c614082 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 1e9e75d..3a34628 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 d62cc48..3d80f0a 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 bb9da94..5573dec 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/SimpleTestInstallBatchTest.php b/core/modules/simpletest/src/Tests/SimpleTestInstallBatchTest.php
index 5663ad9..29da05d 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 42759c2..1364d3c 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 e032cef..0b5f170 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 e57813f..d2c93c5 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 09ec7b4..66b3215 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/Migrate/d6/MigrateSimpletestConfigsTest.php b/core/modules/simpletest/tests/src/Kernel/Migrate/d6/MigrateSimpletestConfigsTest.php
index f8f9ffb..fe70c16 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 6eba633..cc8bd1d 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/statistics/src/Tests/StatisticsTestBase.php b/core/modules/statistics/src/Tests/StatisticsTestBase.php
index 4f530cf..6da2f2c 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 18f5581..4fbd132 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 f4c22bd..900b68d 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 787c35b..c740121 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 09565ae..9877958 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 3be95e2..d55db18 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/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d6/MigrateStatisticsConfigsTest.php
index a9c18a7..18cb50a 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/MigrateStatisticsConfigsTest.php b/core/modules/statistics/tests/src/Kernel/Migrate/d7/MigrateStatisticsConfigsTest.php
index 36e270d..e069b3c 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/syslog/tests/src/Functional/SyslogTest.php b/core/modules/syslog/tests/src/Functional/SyslogTest.php
index 11b577f..ba0cf61 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 935af8d..0552626 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 ef5d8c3..4e50cdc 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 22547f3..850e027 100644
--- a/core/modules/syslog/tests/src/Kernel/SyslogTest.php
+++ b/core/modules/syslog/tests/src/Kernel/SyslogTest.php
@@ -14,7 +14,7 @@
  */
 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 66e06c8..0675692 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 90c548b..daf5aa1 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 96844ed..be15c9e 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/Common/AlterTest.php b/core/modules/system/src/Tests/Common/AlterTest.php
index 863bd54..925f076 100644
--- a/core/modules/system/src/Tests/Common/AlterTest.php
+++ b/core/modules/system/src/Tests/Common/AlterTest.php
@@ -16,7 +16,7 @@ class AlterTest extends WebTestBase {
    *
    * @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/src/Tests/Common/EarlyRenderingControllerTest.php b/core/modules/system/src/Tests/Common/EarlyRenderingControllerTest.php
index 1afdd4e..6588145 100644
--- a/core/modules/system/src/Tests/Common/EarlyRenderingControllerTest.php
+++ b/core/modules/system/src/Tests/Common/EarlyRenderingControllerTest.php
@@ -20,7 +20,7 @@ class EarlyRenderingControllerTest extends WebTestBase {
   /**
    * {@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/src/Tests/Common/FormatDateTest.php b/core/modules/system/src/Tests/Common/FormatDateTest.php
index c174e34..136846f 100644
--- a/core/modules/system/src/Tests/Common/FormatDateTest.php
+++ b/core/modules/system/src/Tests/Common/FormatDateTest.php
@@ -17,7 +17,7 @@ class FormatDateTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * Arbitrary langcode for a custom language.
diff --git a/core/modules/system/src/Tests/Common/RenderWebTest.php b/core/modules/system/src/Tests/Common/RenderWebTest.php
index ed0e086..513a60d 100644
--- a/core/modules/system/src/Tests/Common/RenderWebTest.php
+++ b/core/modules/system/src/Tests/Common/RenderWebTest.php
@@ -19,7 +19,7 @@ class RenderWebTest extends WebTestBase {
    *
    * @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/src/Tests/Common/SimpleTestErrorCollectorTest.php b/core/modules/system/src/Tests/Common/SimpleTestErrorCollectorTest.php
index 9af773b..b4c8f6b 100644
--- a/core/modules/system/src/Tests/Common/SimpleTestErrorCollectorTest.php
+++ b/core/modules/system/src/Tests/Common/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/system/src/Tests/Common/UrlTest.php b/core/modules/system/src/Tests/Common/UrlTest.php
index 1092e1a..a4b8f1c 100644
--- a/core/modules/system/src/Tests/Common/UrlTest.php
+++ b/core/modules/system/src/Tests/Common/UrlTest.php
@@ -20,7 +20,7 @@
  */
 class UrlTest extends WebTestBase {
 
-  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/src/Tests/Condition/ConditionFormTest.php b/core/modules/system/src/Tests/Condition/ConditionFormTest.php
index 42945b2..c853798 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 8a250ba..84f0226 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 7f5c5e3..93700a1 100644
--- a/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
@@ -27,7 +27,7 @@
    *
    * @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/EntityFormTest.php b/core/modules/system/src/Tests/Entity/EntityFormTest.php
index 2ebc350..42dffec 100644
--- a/core/modules/system/src/Tests/Entity/EntityFormTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityFormTest.php
@@ -17,7 +17,7 @@ class EntityFormTest extends WebTestBase {
    *
    * @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/src/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
index f513424..0a9e823 100644
--- a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
@@ -19,7 +19,7 @@ class EntityTranslationFormTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['entity_test', 'language', 'node'];
+  protected static $modules = ['entity_test', 'language', 'node'];
 
   protected $langcodes;
 
diff --git a/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php b/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
index 5d7dc6f..35c7202 100644
--- a/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
+++ b/core/modules/system/src/Tests/Entity/EntityUnitTestBase.php
@@ -20,7 +20,7 @@
    *
    * @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 d335518..442c061 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 2e138bd..bd48f04 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 a1f7fee..8f32596 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 fb59cb5..54a4039 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 6c5ce54..5411c82 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/InstallUninstallTest.php b/core/modules/system/src/Tests/Module/InstallUninstallTest.php
index a78918b..f1579c9 100644
--- a/core/modules/system/src/Tests/Module/InstallUninstallTest.php
+++ b/core/modules/system/src/Tests/Module/InstallUninstallTest.php
@@ -15,7 +15,7 @@ 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/src/Tests/Module/ModuleTestBase.php b/core/modules/system/src/Tests/Module/ModuleTestBase.php
index cc5a7ef..a561106 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/Module/PrepareUninstallTest.php b/core/modules/system/src/Tests/Module/PrepareUninstallTest.php
index dd89e31..4d29d6b 100644
--- a/core/modules/system/src/Tests/Module/PrepareUninstallTest.php
+++ b/core/modules/system/src/Tests/Module/PrepareUninstallTest.php
@@ -34,7 +34,7 @@ class PrepareUninstallTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'taxonomy', 'entity_test'];
+  protected static $modules = ['node', 'taxonomy', 'entity_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Tests/Pager/PagerTest.php b/core/modules/system/src/Tests/Pager/PagerTest.php
index 71413f2..511e40e 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 6060fcc..3ef9cf1 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 a55037f..da60ac5 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 d959c7a..c6669af 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 38d7ecb..56cf46e 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 ffdc08d..48f629e 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 6ba70da..81e3b66 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 1be9561..d3e4196 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 ac36868..da57363 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/AccessDeniedTest.php b/core/modules/system/src/Tests/System/AccessDeniedTest.php
index ba1d599..040b31f 100644
--- a/core/modules/system/src/Tests/System/AccessDeniedTest.php
+++ b/core/modules/system/src/Tests/System/AccessDeniedTest.php
@@ -18,7 +18,7 @@ class AccessDeniedTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['block', 'node', 'system_test'];
+  protected static $modules = ['block', 'node', 'system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/src/Tests/System/AdminTest.php b/core/modules/system/src/Tests/System/AdminTest.php
index 7921e1c..97c7ebb 100644
--- a/core/modules/system/src/Tests/System/AdminTest.php
+++ b/core/modules/system/src/Tests/System/AdminTest.php
@@ -31,7 +31,7 @@ class AdminTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['locale'];
+  protected static $modules = ['locale'];
 
   protected function setUp() {
     // testAdminPages() requires Locale module.
diff --git a/core/modules/system/src/Tests/System/CronRunTest.php b/core/modules/system/src/Tests/System/CronRunTest.php
index ec4e649..7004c9d 100644
--- a/core/modules/system/src/Tests/System/CronRunTest.php
+++ b/core/modules/system/src/Tests/System/CronRunTest.php
@@ -16,7 +16,7 @@ class CronRunTest extends WebTestBase {
    *
    * @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/src/Tests/System/ErrorHandlerTest.php b/core/modules/system/src/Tests/System/ErrorHandlerTest.php
index dc661fe..04cb175 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/src/Tests/System/FrontPageTest.php b/core/modules/system/src/Tests/System/FrontPageTest.php
index e24e90c..5378b9b 100644
--- a/core/modules/system/src/Tests/System/FrontPageTest.php
+++ b/core/modules/system/src/Tests/System/FrontPageTest.php
@@ -17,7 +17,7 @@ class FrontPageTest extends WebTestBase {
    *
    * @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/src/Tests/System/HtaccessTest.php b/core/modules/system/src/Tests/System/HtaccessTest.php
index fab7a37..7f47821 100644
--- a/core/modules/system/src/Tests/System/HtaccessTest.php
+++ b/core/modules/system/src/Tests/System/HtaccessTest.php
@@ -16,7 +16,7 @@ class HtaccessTest extends WebTestBase {
    *
    * @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/src/Tests/System/PageNotFoundTest.php b/core/modules/system/src/Tests/System/PageNotFoundTest.php
index b1a88d8..04ed2a3 100644
--- a/core/modules/system/src/Tests/System/PageNotFoundTest.php
+++ b/core/modules/system/src/Tests/System/PageNotFoundTest.php
@@ -18,7 +18,7 @@ class PageNotFoundTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/src/Tests/System/PageTitleTest.php b/core/modules/system/src/Tests/System/PageTitleTest.php
index 44e33cb..e0301f4 100644
--- a/core/modules/system/src/Tests/System/PageTitleTest.php
+++ b/core/modules/system/src/Tests/System/PageTitleTest.php
@@ -18,7 +18,7 @@ class PageTitleTest extends WebTestBase {
    *
    * @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/src/Tests/System/ResponseGeneratorTest.php b/core/modules/system/src/Tests/System/ResponseGeneratorTest.php
index a535b66..b5d9e16 100644
--- a/core/modules/system/src/Tests/System/ResponseGeneratorTest.php
+++ b/core/modules/system/src/Tests/System/ResponseGeneratorTest.php
@@ -16,7 +16,7 @@ class ResponseGeneratorTest extends RESTTestBase {
    *
    * @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/src/Tests/System/ShutdownFunctionsTest.php b/core/modules/system/src/Tests/System/ShutdownFunctionsTest.php
index 50fae03..2b43149 100644
--- a/core/modules/system/src/Tests/System/ShutdownFunctionsTest.php
+++ b/core/modules/system/src/Tests/System/ShutdownFunctionsTest.php
@@ -16,7 +16,7 @@ class ShutdownFunctionsTest extends WebTestBase {
    *
    * @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/src/Tests/System/SiteMaintenanceTest.php b/core/modules/system/src/Tests/System/SiteMaintenanceTest.php
index e269a6c..aa5ef6d 100644
--- a/core/modules/system/src/Tests/System/SiteMaintenanceTest.php
+++ b/core/modules/system/src/Tests/System/SiteMaintenanceTest.php
@@ -17,7 +17,7 @@ class SiteMaintenanceTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['node'];
+  protected static $modules = ['node'];
 
   protected $adminUser;
 
diff --git a/core/modules/system/src/Tests/System/ThemeTest.php b/core/modules/system/src/Tests/System/ThemeTest.php
index 29d88a3..9b3706c 100644
--- a/core/modules/system/src/Tests/System/ThemeTest.php
+++ b/core/modules/system/src/Tests/System/ThemeTest.php
@@ -25,7 +25,7 @@ class ThemeTest extends WebTestBase {
    *
    * @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/src/Tests/System/TokenReplaceWebTest.php b/core/modules/system/src/Tests/System/TokenReplaceWebTest.php
index 21fe23a..b652e1c 100644
--- a/core/modules/system/src/Tests/System/TokenReplaceWebTest.php
+++ b/core/modules/system/src/Tests/System/TokenReplaceWebTest.php
@@ -18,7 +18,7 @@ class TokenReplaceWebTest extends WebTestBase {
   /**
    * {@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/src/Tests/System/UncaughtExceptionTest.php b/core/modules/system/src/Tests/System/UncaughtExceptionTest.php
index 02c0956..28be3e9 100644
--- a/core/modules/system/src/Tests/System/UncaughtExceptionTest.php
+++ b/core/modules/system/src/Tests/System/UncaughtExceptionTest.php
@@ -23,7 +23,7 @@ class UncaughtExceptionTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['error_service_test'];
+  protected static $modules = ['error_service_test'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Tests/Theme/EngineTwigTest.php b/core/modules/system/src/Tests/Theme/EngineTwigTest.php
index ffff75f..f82b56a 100644
--- a/core/modules/system/src/Tests/Theme/EngineTwigTest.php
+++ b/core/modules/system/src/Tests/Theme/EngineTwigTest.php
@@ -18,7 +18,7 @@ class EngineTwigTest extends WebTestBase {
    *
    * @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/src/Tests/Theme/FunctionsTest.php b/core/modules/system/src/Tests/Theme/FunctionsTest.php
index 8258348..d6db0d5 100644
--- a/core/modules/system/src/Tests/Theme/FunctionsTest.php
+++ b/core/modules/system/src/Tests/Theme/FunctionsTest.php
@@ -21,7 +21,7 @@ class FunctionsTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['router_test'];
+  protected static $modules = ['router_test'];
 
   /**
    * Tests item-list.html.twig.
diff --git a/core/modules/system/src/Tests/Theme/HtmlAttributesTest.php b/core/modules/system/src/Tests/Theme/HtmlAttributesTest.php
index b2018c7..a38e4dc 100644
--- a/core/modules/system/src/Tests/Theme/HtmlAttributesTest.php
+++ b/core/modules/system/src/Tests/Theme/HtmlAttributesTest.php
@@ -16,7 +16,7 @@ class HtmlAttributesTest extends WebTestBase {
    *
    * @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/src/Tests/Theme/ThemeSuggestionsAlterTest.php b/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
index c01a94f..54b6e46 100644
--- a/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
@@ -17,7 +17,7 @@ class ThemeSuggestionsAlterTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test'];
+  protected static $modules = ['theme_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Theme/ThemeTest.php b/core/modules/system/src/Tests/Theme/ThemeTest.php
index 64f330e..a157c1e 100644
--- a/core/modules/system/src/Tests/Theme/ThemeTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeTest.php
@@ -22,7 +22,7 @@ class ThemeTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['theme_test', 'node'];
+  protected static $modules = ['theme_test', 'node'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php b/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
index 457fbad..4ce16af 100644
--- a/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
@@ -16,7 +16,7 @@ class TwigDebugMarkupTest extends WebTestBase {
    *
    * @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/src/Tests/Theme/TwigFilterTest.php b/core/modules/system/src/Tests/Theme/TwigFilterTest.php
index 653e4fa..1564a27 100644
--- a/core/modules/system/src/Tests/Theme/TwigFilterTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigFilterTest.php
@@ -16,7 +16,7 @@ class TwigFilterTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['twig_theme_test'];
+  protected static $modules = ['twig_theme_test'];
 
   /**
    * Test Twig "without" filter.
diff --git a/core/modules/system/src/Tests/Theme/TwigNamespaceTest.php b/core/modules/system/src/Tests/Theme/TwigNamespaceTest.php
index ab62889..c07aca7 100644
--- a/core/modules/system/src/Tests/Theme/TwigNamespaceTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigNamespaceTest.php
@@ -16,7 +16,7 @@ class TwigNamespaceTest extends WebTestBase {
    *
    * @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/src/Tests/Theme/TwigRawTest.php b/core/modules/system/src/Tests/Theme/TwigRawTest.php
index 8be63db..7c84589 100644
--- a/core/modules/system/src/Tests/Theme/TwigRawTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigRawTest.php
@@ -16,7 +16,7 @@ class TwigRawTest extends WebTestBase {
    *
    * @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/src/Tests/Theme/TwigTransTest.php b/core/modules/system/src/Tests/Theme/TwigTransTest.php
index b73cdaf..7ecbc26 100644
--- a/core/modules/system/src/Tests/Theme/TwigTransTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigTransTest.php
@@ -17,7 +17,7 @@ class TwigTransTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'theme_test',
     'twig_theme_test',
     'locale',
diff --git a/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php b/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
index 222ebc4..8b019ae 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 b1e46a2..957c802 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 2d7c7ae..24e83fb 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/DrupalSetMessageTest.php b/core/modules/system/tests/src/Functional/Bootstrap/DrupalSetMessageTest.php
index 976e8be..246c659 100644
--- a/core/modules/system/tests/src/Functional/Bootstrap/DrupalSetMessageTest.php
+++ b/core/modules/system/tests/src/Functional/Bootstrap/DrupalSetMessageTest.php
@@ -16,7 +16,7 @@ class DrupalSetMessageTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['system_test'];
+  protected static $modules = ['system_test'];
 
   /**
    * Tests drupal_set_message().
diff --git a/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php b/core/modules/system/tests/src/Functional/Cache/SessionExistsCacheContextTest.php
index 78fb983..d2ff3d3 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/CsrfRequestHeaderTest.php b/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
index c6d7b35..9549763 100644
--- a/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
+++ b/core/modules/system/tests/src/Functional/CsrfRequestHeaderTest.php
@@ -18,7 +18,7 @@ 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 a28c1db..9193ee1 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 5226585..a5f0385 100644
--- a/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
+++ b/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
@@ -12,7 +12,7 @@ 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 d2114fd..567748b 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 828b92f..37e6424 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 6c5a9d6..58edb42 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'];
+  protected static $modules = ['action', 'block', 'filter', 'image', 'search', 'search_extra_type'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php b/core/modules/system/tests/src/Functional/Entity/EntityAddUITest.php
index a16614f..756ebb5 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 1476dfa..f809ace 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/EntityListBuilderTest.php b/core/modules/system/tests/src/Functional/Entity/EntityListBuilderTest.php
index 94225f4..fe6bb2a 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 b020f42..fc17850 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 3772f3a..5677908 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
@@ -26,7 +26,7 @@ class EntityReferenceSelectionAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  protected static $modules = ['node', 'comment'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
index caf5fa2..7f531fe 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityRevisionsTest.php
@@ -19,7 +19,7 @@ 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/EntityViewControllerTest.php b/core/modules/system/tests/src/Functional/Entity/EntityViewControllerTest.php
index 3637369..2fc1c09 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 622a3d1..f857f47 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 e35ac6d..9d243ba 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 60fad6a..40eb6a4 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 c65546a..811fa5d 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 57da8da..10de212 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 1a92893..039ada3 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 a7d404b..8a555d7 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 6747ed6..041c3c2 100644
--- a/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php
+++ b/core/modules/system/tests/src/Functional/Form/ElementsLabelsTest.php
@@ -16,7 +16,7 @@ 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 07f25fe..a2c933b 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 2fe6ebe..6468a36 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 34ebb2e..3a0c91e 100644
--- a/core/modules/system/tests/src/Functional/Form/FormObjectTest.php
+++ b/core/modules/system/tests/src/Functional/Form/FormObjectTest.php
@@ -17,7 +17,7 @@ class FormObjectTest extends SystemConfigFormTestBase {
    *
    * @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/Functional/Form/FormStoragePageCacheTest.php b/core/modules/system/tests/src/Functional/Form/FormStoragePageCacheTest.php
index 474a35b..c5d2357 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 87c7632..f05572c 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 1bfa19f..c684984 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 dc63e64..7420ded 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 a4c9e15..66f97d0 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 de5d8fd..a043c46 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 63d8e70..d5b109b 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 6266487..07dea28 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 09ad06a..c3304fb 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 82d227b..c4d2c61 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 094a0af..799b2da 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/Lock/LockFunctionalTest.php b/core/modules/system/tests/src/Functional/Lock/LockFunctionalTest.php
index 0b13f18..7af09ad 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 74549a3..f5ab88c 100644
--- a/core/modules/system/tests/src/Functional/Mail/MailTest.php
+++ b/core/modules/system/tests/src/Functional/Mail/MailTest.php
@@ -18,7 +18,7 @@ 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 e9142dc..50391b3 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 f7b9aaf..2a78b11 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 12a157d..458a226 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'];
+  protected static $modules = ['block', 'menu_test', 'entity_test'];
 
   /**
    * 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 10af396..2c95315 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 c58bf8e..8432a67 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 7669e18..e30eaef 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 ccbca6d..8026549 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/ModuleTestBase.php b/core/modules/system/tests/src/Functional/Module/ModuleTestBase.php
index abdbe03..1f29537 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/UninstallTest.php b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
index 2b17b8f..498d11d 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 faafe84..404137a 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 2717741..3c1d7e3 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 6f5dc7d..ad38d33 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 2f5415b..47517ed 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 185ca49..0d7a1e9 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 08380de..08674b8 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/Routing/RouterPermissionTest.php b/core/modules/system/tests/src/Functional/Routing/RouterPermissionTest.php
index 62a511f..4071d84 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 73d6910..f71c18c 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/DateTimeTest.php b/core/modules/system/tests/src/Functional/System/DateTimeTest.php
index bdecab5..900ada6 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/MainContentFallbackTest.php b/core/modules/system/tests/src/Functional/System/MainContentFallbackTest.php
index 931b84c..d197d4a 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/StatusTest.php b/core/modules/system/tests/src/Functional/System/StatusTest.php
index 1ec4fb5..45ebe8d 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 b3f9b31..42af534 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/Theme/EngineNyanCatTest.php b/core/modules/system/tests/src/Functional/Theme/EngineNyanCatTest.php
index 6dca1b3..0f0c3ef 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/FastTest.php b/core/modules/system/tests/src/Functional/Theme/FastTest.php
index d8f85f1..188b236 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/ThemeEarlyInitializationTest.php b/core/modules/system/tests/src/Functional/Theme/ThemeEarlyInitializationTest.php
index 040dfab..c955628 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 e372bb2..5aa1642 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/TwigExtensionTest.php b/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
index 5e3bc72..fff6067 100644
--- a/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
+++ b/core/modules/system/tests/src/Functional/Theme/TwigExtensionTest.php
@@ -16,7 +16,7 @@ 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 d2b0b54..af7bea3 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 2446289..d6cd472 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 0ad88ce..696e07a 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/Update/DependencyHookInvocationTest.php b/core/modules/system/tests/src/Functional/Update/DependencyHookInvocationTest.php
index 8ff7b88..9e6a146 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 6ae4dc4..97b320d 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 8cafaad..df65025 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 44d4832..926d9dd 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 a42cbcb..412567c 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 29d4d08..b723a09 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 2452264..5a9e2c0 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 7c0aec0..16143da 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 JavascriptTestBase {
   /**
    * {@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 567919c..87fac5f 100644
--- a/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php
+++ b/core/modules/system/tests/src/FunctionalJavascript/OffCanvasTest.php
@@ -12,7 +12,7 @@ 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 8e4729f..1f76459 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 JavascriptTestBase {
   /**
    * {@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 6c381d7..6a2c7c6 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 663bff6..850b5e8 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/DateFormatAccessControlHandlerTest.php b/core/modules/system/tests/src/Kernel/DateFormatAccessControlHandlerTest.php
index 01b09dc..d5767ed 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 f7fa5d8..30041d3 100644
--- a/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php
+++ b/core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelectionReferenceableTest.php
@@ -42,7 +42,7 @@ 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 d7c2650..3b03ba5 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 2bc895f..5a7992c 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 94026b6..480ccb3 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/ProgrammaticTest.php b/core/modules/system/tests/src/Kernel/Form/ProgrammaticTest.php
index 03d22af..1d41fbe 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 052c0af..226c5dc 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 f359153..cc94bc2 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 6d702c7..9291db9 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 33c963d..c5181de 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 56ee5b6..73bfef9 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 0216e2d..dd93331 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/Plugin/migrate/source/MenuTest.php b/core/modules/system/tests/src/Kernel/Plugin/migrate/source/MenuTest.php
index 0feb9a2..3917b37 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 17b54fa..482e4dd 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 8dbb01e..1f304e8 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 a2ca864..3e6ec4c 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 8a292e5..e489371 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 649a2c7..f5e13bf 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 ebdac3c..3c64d29 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/Timezone/TimezoneTest.php b/core/modules/system/tests/src/Kernel/Timezone/TimezoneTest.php
index 8a5385c..42ff81c 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 2c83390..3ebf352 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 81a397d..930acc9 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 599b6fb..6701e53 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 b4f941d..4ca7868 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 42f92b1..22c0094 100644
--- a/core/modules/taxonomy/src/Tests/TermTest.php
+++ b/core/modules/taxonomy/src/Tests/TermTest.php
@@ -35,7 +35,7 @@ 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 ccb16f6..8e32362 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/LegacyTest.php b/core/modules/taxonomy/tests/src/Functional/LegacyTest.php
index 667ed55..da6a29f 100644
--- a/core/modules/taxonomy/tests/src/Functional/LegacyTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/LegacyTest.php
@@ -18,7 +18,7 @@ class LegacyTest 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/TaxonomyImageTest.php b/core/modules/taxonomy/tests/src/Functional/TaxonomyImageTest.php
index 504c0da..e507b25 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 85310e9..05caded 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 66782f3..0a72651 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 fdbfccd..51df0af 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 35b7d6b..1fda920 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/TermEntityReferenceTest.php b/core/modules/taxonomy/tests/src/Functional/TermEntityReferenceTest.php
index 9d4522e..3509822 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 d4fe8f2..0ebc01a 100644
--- a/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/TermIndexTest.php
@@ -17,7 +17,7 @@ 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 f60e77e..8de70dc 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 236ac70..bb18e31 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 0d24b69..f068173 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 a7ac9b8..5f44715 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 1b8bbca..c688178 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 6fd1eba..b459304 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 4de7370..63340ed 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 d8ab8ea..40985e7 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 3505784..c37b9a5 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 4d7a4fd..3b06531 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 5f70d90..5229dc0 100644
--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyTermViewTest.php
@@ -22,7 +22,7 @@ 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 a2d8ec1..0eb4cbf 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 8b1d58c..721df17 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 2ac2d9d..ea4ad7b 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyCrudTest.php
@@ -19,7 +19,7 @@ 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 f25df8a..95b7a9a 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyLanguageTest.php
@@ -13,7 +13,7 @@
  */
 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 989398e..5176cf3 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 b9aba8a..16621b3 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 2d31257..b54073b 100644
--- a/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/VocabularyTranslationTest.php
@@ -14,7 +14,7 @@ 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 92ebe59..e048017 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 2da51e4..1d340fc 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 6450e4d..5dadaec 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/MigrateTaxonomyTermTranslationTest.php b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
index d21ad1e..a82df35 100644
--- a/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/Migrate/d6/MigrateTaxonomyTermTranslationTest.php
@@ -16,7 +16,7 @@ class MigrateTaxonomyTermTranslationTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = [
+  protected static $modules = [
     'language',
     'menu_ui',
     'node',
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 79e188b..ac386c7 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 3993abb..4d3367c 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 = ['language', 'taxonomy'];
+  protected static $modules = ['language', 'taxonomy'];
 
   /**
    * {@inheritdoc}
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 614725d..1269f22 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 8e7d13d..eb8e092 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 5b8a638..1599fe7 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 2c96e51..06a6624 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 26cd7f5..aef587f 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 d294ec4..9264e9f 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 e8c6fef..c7b5738 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 474969d..3ed243a 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 5663ea6..10220bd 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 e4b2cc0..ed9acf6 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 3084acf..16a365a 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 42fa75d..bb60f9c 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 d1ac238..c0b50cb 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 af69e30..cafbc81 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 a98b298..4b81b6c 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 e54eb6e..1c5522c 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 e03a6ab..a6bdb52 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 dd22672..eb3753e 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 4d1975c..fb78c54 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 3d8bff8..a9b1f5d 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 437a305..9778467 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/TaxonomyViewsFieldAccessTest.php b/core/modules/taxonomy/tests/src/Kernel/Views/TaxonomyViewsFieldAccessTest.php
index e62232b..2d7b960 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 18bedf0..a48cda7 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 7226940..11b6512 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/Kernel/TextFormatterTest.php b/core/modules/text/tests/src/Kernel/TextFormatterTest.php
index c75ac34..d75bcc4 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 dab6ed5..d9042ec 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 a48c191..7ae5fb4 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 9585c86..400cb97 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 2645476..d9d27d4 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 f3d3ce6..19ebfc6 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 995d49e..a954a85 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 c3b3d9a..2d05cfa 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 JavascriptTestBase {
   /**
    * {@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/TourCacheTagsTest.php b/core/modules/tour/tests/src/Functional/TourCacheTagsTest.php
index daed6fa..32621bc 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 ad60df1..de8fb30 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 55f3743..45d755c 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 ce47467..732f912 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 9746a22..079cdc9 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 2b320ae..8fa2b89 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 1a77d95..535c52c 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 d706843..0c7ebdd 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 d370502..fa0674f 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 ea97322..552774b 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 3b0c11b..2282070 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 0318b8e..3457c8f 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 ffcee93..8612cfa 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 d768b06..cac8512 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 20d397c..a9c7c53 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 5cd4b10..6d7b5e8 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 601a6cc..2724693 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 6096620..0b5d60f 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 aa3563c..a7d2349 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/RestRegisterUserTest.php b/core/modules/user/src/Tests/RestRegisterUserTest.php
index 450c552..c53bd7c 100644
--- a/core/modules/user/src/Tests/RestRegisterUserTest.php
+++ b/core/modules/user/src/Tests/RestRegisterUserTest.php
@@ -16,7 +16,7 @@ class RestRegisterUserTest extends RESTTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['hal'];
+  protected static $modules = ['hal'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/UserAccountLinksTest.php b/core/modules/user/src/Tests/UserAccountLinksTest.php
index 15a4b20..0338c5c 100644
--- a/core/modules/user/src/Tests/UserAccountLinksTest.php
+++ b/core/modules/user/src/Tests/UserAccountLinksTest.php
@@ -16,7 +16,7 @@ class UserAccountLinksTest extends WebTestBase {
    *
    * @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/src/Tests/UserAdminLanguageTest.php b/core/modules/user/src/Tests/UserAdminLanguageTest.php
index cd6cc65..be5453d 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/UserAdminTest.php b/core/modules/user/src/Tests/UserAdminTest.php
index f3ee85a..10b1763 100644
--- a/core/modules/user/src/Tests/UserAdminTest.php
+++ b/core/modules/user/src/Tests/UserAdminTest.php
@@ -17,7 +17,7 @@ class UserAdminTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy', 'views'];
+  protected static $modules = ['taxonomy', 'views'];
 
   /**
    * Registers a user and deletes it.
diff --git a/core/modules/user/src/Tests/UserBlocksTest.php b/core/modules/user/src/Tests/UserBlocksTest.php
index 0a4c619..3032ccc 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 7b53443..049019e 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/UserLanguageCreationTest.php b/core/modules/user/src/Tests/UserLanguageCreationTest.php
index 0dd2907..a8cb557 100644
--- a/core/modules/user/src/Tests/UserLanguageCreationTest.php
+++ b/core/modules/user/src/Tests/UserLanguageCreationTest.php
@@ -18,7 +18,7 @@ class UserLanguageCreationTest extends WebTestBase {
    *
    * @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/src/Tests/UserPasswordResetTest.php b/core/modules/user/src/Tests/UserPasswordResetTest.php
index 88fe72c..de704a6 100644
--- a/core/modules/user/src/Tests/UserPasswordResetTest.php
+++ b/core/modules/user/src/Tests/UserPasswordResetTest.php
@@ -37,7 +37,7 @@ class UserPasswordResetTest extends PageCacheTagsTestBase {
    *
    * @var array
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/UserRegistrationTest.php b/core/modules/user/src/Tests/UserRegistrationTest.php
index 128b71b..bf42b9a 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/src/Tests/UserRoleAdminTest.php b/core/modules/user/src/Tests/UserRoleAdminTest.php
index eca9915..64e1669 100644
--- a/core/modules/user/src/Tests/UserRoleAdminTest.php
+++ b/core/modules/user/src/Tests/UserRoleAdminTest.php
@@ -25,7 +25,7 @@ class UserRoleAdminTest extends WebTestBase {
    *
    * @var string[]
    */
-  public static $modules = ['block'];
+  protected static $modules = ['block'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/user/src/Tests/UserTimeZoneTest.php b/core/modules/user/src/Tests/UserTimeZoneTest.php
index 396add4..5ca371a 100644
--- a/core/modules/user/src/Tests/UserTimeZoneTest.php
+++ b/core/modules/user/src/Tests/UserTimeZoneTest.php
@@ -17,7 +17,7 @@ class UserTimeZoneTest extends WebTestBase {
    *
    * @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/src/Tests/UserTranslationUITest.php b/core/modules/user/src/Tests/UserTranslationUITest.php
index 32a9b8f..1ba44f5 100644
--- a/core/modules/user/src/Tests/UserTranslationUITest.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/AccessTestBase.php b/core/modules/user/src/Tests/Views/AccessTestBase.php
index b0395b0..6f117d5 100644
--- a/core/modules/user/src/Tests/Views/AccessTestBase.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/BulkFormAccessTest.php b/core/modules/user/src/Tests/Views/BulkFormAccessTest.php
index a6ab3c8..31a0937 100644
--- a/core/modules/user/src/Tests/Views/BulkFormAccessTest.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/BulkFormTest.php b/core/modules/user/src/Tests/Views/BulkFormTest.php
index 665af74..1e3c5f8 100644
--- a/core/modules/user/src/Tests/Views/BulkFormTest.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/FilterPermissionUiTest.php b/core/modules/user/src/Tests/Views/FilterPermissionUiTest.php
index f9444bc..53b8906 100644
--- a/core/modules/user/src/Tests/Views/FilterPermissionUiTest.php
+++ b/core/modules/user/src/Tests/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() {
     parent::setUp(TRUE);
diff --git a/core/modules/user/src/Tests/Views/HandlerFilterUserNameTest.php b/core/modules/user/src/Tests/Views/HandlerFilterUserNameTest.php
index 4f7d4cd..fd6c8ee 100644
--- a/core/modules/user/src/Tests/Views/HandlerFilterUserNameTest.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/UserChangedTest.php b/core/modules/user/src/Tests/Views/UserChangedTest.php
index ddd7903..48b77c9 100644
--- a/core/modules/user/src/Tests/Views/UserChangedTest.php
+++ b/core/modules/user/src/Tests/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/src/Tests/Views/UserTestBase.php b/core/modules/user/src/Tests/Views/UserTestBase.php
index c49dcb2..ce338a6 100644
--- a/core/modules/user/src/Tests/Views/UserTestBase.php
+++ b/core/modules/user/src/Tests/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/Functional/AccessRoleUITest.php b/core/modules/user/tests/src/Functional/AccessRoleUITest.php
index 6c1004c..e33d9b5 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/UserCacheTagsTest.php b/core/modules/user/tests/src/Functional/UserCacheTagsTest.php
index a9e9857..56542ea 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 9889cd6..7c73c0c 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 38f2514..5c23f4b 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 feea805..e3626a9 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/UserLanguageTest.php b/core/modules/user/tests/src/Functional/UserLanguageTest.php
index 0e6c0f1..8553017 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 b12a72b..0e8a907 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/UserSearchTest.php b/core/modules/user/tests/src/Functional/UserSearchTest.php
index 8ce0319..ef7cd22 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/UserTokenReplaceTest.php b/core/modules/user/tests/src/Functional/UserTokenReplaceTest.php
index e272b60..9cf2202 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/Kernel/Condition/UserRoleConditionTest.php b/core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
index 075b04c..5646aaa 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 6beecb8..e91f4fe 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 85cd761..a54f797 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 0d3bb7c..8a4f1a1 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 f753824..f501012 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 9b3829e..e9a8e62 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 1389693..fac8122 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 9713332..0625c70 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 768f5d7..3c25c70 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 fcdaa25..b1e3ac11 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 e734517..9452341 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 ed28777..b87708d 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 bbfc41d..a25b275 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',
     'datetime',
     'file',
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 c321185..dadcaaa 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 d9e77ed..a87ede1 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 26c2ed5..2e3aba4 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 1a841d3..d37659b 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 2724d35..c77b45c 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 aea6afa..2eb61d8 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 1dc34a7..19f85be 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 d2d43a4..885894c 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/UserTest.php b/core/modules/user/tests/src/Kernel/Plugin/migrate/source/d7/UserTest.php
index 8e14d63..6e0feb2 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 b3d7ff1..6696bb2 100644
--- a/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
+++ b/core/modules/user/tests/src/Kernel/TempStoreDatabaseTest.php
@@ -21,7 +21,7 @@ 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 6433021..49fb38c 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 dfafb1d..d6e5c35 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 73fe869..a05c648 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 672ddb0..ee5bf39 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 f61811b..a92ca80 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 cac470a..ee7f881 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 562ada1..b597c3d 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 17364c0..093c6bf 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/UserValidationTest.php b/core/modules/user/tests/src/Kernel/UserValidationTest.php
index 4aa5850..bc8e061 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 0e862c8..dc6cd31 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 f14779e..e20a01b 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/views/src/Tests/FieldApiDataTest.php b/core/modules/views/src/Tests/FieldApiDataTest.php
index f6d5159..dcfdd06 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 e8d2549..29259e7 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() {
     parent::setUp();
diff --git a/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php b/core/modules/views/src/Tests/Plugin/StyleOpmlTest.php
index 4e84433..05fbbd1 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 5a23285..452d24e 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 e1e5190..9db2136 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 ba7509c..8f09eb2 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() {
     parent::setUp();
diff --git a/core/modules/views/tests/src/Functional/DefaultViewsTest.php b/core/modules/views/tests/src/Functional/DefaultViewsTest.php
index 9e4c338..2997776 100644
--- a/core/modules/views/tests/src/Functional/DefaultViewsTest.php
+++ b/core/modules/views/tests/src/Functional/DefaultViewsTest.php
@@ -29,7 +29,7 @@ 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 19aa191..876d1ab 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 a46e54c..1163b43 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 2a227c5..3d62103 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 993293c..c39b564 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 d73a117..3d97800 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 911cd61..0b9d011 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 d67f70d..e54ee8b 100644
--- a/core/modules/views/tests/src/Functional/GlossaryTest.php
+++ b/core/modules/views/tests/src/Functional/GlossaryTest.php
@@ -22,7 +22,7 @@ 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/Handler/AreaHTTPStatusCodeTest.php b/core/modules/views/tests/src/Functional/Handler/AreaHTTPStatusCodeTest.php
index dc914ce..82923c9 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 d631373..326c2d3 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 17ece94..a1a57f7 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 e0e380b..b3c2b80 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 7ced4f7..028973c 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 d38ba41..b2d96ad 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 275960c..0efbd51 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 a3646f0..7b4df31 100644
--- a/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php
+++ b/core/modules/views/tests/src/Functional/Handler/FieldWebTest.php
@@ -31,7 +31,7 @@ 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 ec3b523..6e52bac 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/HandlerAllTest.php b/core/modules/views/tests/src/Functional/Handler/HandlerAllTest.php
index 1a37ce8..b81ef29 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 cffe6d1..1522f8d 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 41aa6ec..8d78835 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 {
    *
    * @return 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 57eb232..b4a0bfe 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 1d78204..79273d0 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 f8ce5a9..19dc5c9 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 215ee28..36f82bb 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 708ac55..7b00ea5 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 8c326ba..ac62351 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 daad148..c648607 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 501d922..c31698a 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 6748152..66831e0 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 80584d7..e8404c3 100644
--- a/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php
+++ b/core/modules/views/tests/src/Functional/Plugin/ExposedFormCheckboxesTest.php
@@ -28,7 +28,7 @@ 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 eaa5aaa..b46725d 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 6042410..6cf285e 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 8afbb57..c452084 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 492d22f..d8d7507 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 08f2504..e72a2b2 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 c80fa09..b745ea6 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 a2359b9..77674e2 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 1b3078b..950379f 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 3f6e1ec..9ad5e43 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 f8dfdd8..c297b7e 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/SearchIntegrationTest.php b/core/modules/views/tests/src/Functional/SearchIntegrationTest.php
index f4daac7..7954dec 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 d6a72bf..1849306 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 fbf5f41..1f7a4c6 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 10bc5d4..ec499ae 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 80a8398..90443ba 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 9bdb405..4db8a0f 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 680d644..7067a6b 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 0178c08..924db29 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 0e5095d..e000ed6 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 JavascriptTestBase {
   /**
    * {@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 974aa2d..cbf17d6 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 JavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['node', 'views'];
+  protected static $modules = ['node', 'views'];
 
   /**
    * Tests if exposed filtering via AJAX works for the "Content" View.
diff --git a/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php b/core/modules/views/tests/src/FunctionalJavascript/GlossaryViewTest.php
index 3611829..ab30b76 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 JavascriptTestBase {
   /**
    * {@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 850c553..ad58e10 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 JavascriptTestBase {
   /**
    * {@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 dd1d1ae..8ab0cd9 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 JavascriptTestBase {
   /**
    * {@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 76f0ff1..bb80027 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 JavascriptTestBase {
   /**
    * {@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 9a9b2da..de7c2af 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 JavascriptTestBase {
   /**
    * {@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 edf0fb0..3a5014f 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 a110f00..961de79 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 4929c7e..b4ff752 100644
--- a/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php
+++ b/core/modules/views/tests/src/Kernel/Entity/ViewEntityDependenciesTest.php
@@ -30,7 +30,7 @@ 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 2319a70..3d55196 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 0f209ca..63c434b 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 a95214a..833316e 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 84a66ab..e670eab 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 2feaaf1..0cf95c3 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 6eaba13..69b75c7 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 8f85f69..c6486d8 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'];
 
 
   /**
diff --git a/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php b/core/modules/views/tests/src/Kernel/Handler/EntityTestViewsFieldAccessTest.php
index ee219ab..e485d16 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 b5c52fe..ca9f1ed 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 b789bd6..ffc1a80 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 a7f5116..065c78c 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 5ff77bc..37e1f4e 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 1d304f5..7501a3f 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'];
+  protected static $modules = ['field', 'entity_test', 'user', 'views_test_formatter'];
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php b/core/modules/views/tests/src/Kernel/Handler/FieldKernelTest.php
index 677a3f5..2faef9f 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 02419f4..f49d682 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 0814402..61d2cb5 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 7beceb9..cf4f1b1 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 325da51..5495cea 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 7cdd41f..e653cbb 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 feffbaf..fb5c8e6 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 d78f7c9..1138c54 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 e02a843..a78d0bb 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 e1093e4..53b72f2 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 03c1b87..71e7186 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 53d25b3..16c0e19 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 e49ef7a..6f21954 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 9fe9df6..d8d287d 100644
--- a/core/modules/views/tests/src/Kernel/ModuleTest.php
+++ b/core/modules/views/tests/src/Kernel/ModuleTest.php
@@ -26,7 +26,7 @@ class ModuleTest extends ViewsKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['field', 'user', 'block'];
+  protected static $modules = ['field', 'user', 'block'];
 
   /**
    * Stores the last triggered error, for example via debug().
diff --git a/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php b/core/modules/views/tests/src/Kernel/Plugin/BlockDependenciesTest.php
index 1a9f32e..07fb822 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 9f6066e..57150a0 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 d08adaa..4a49038 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 69666cf..6496623 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 3232ecb..25a3ff4 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'];
+  protected static $modules = ['system', 'user', 'field'];
 
   /**
    * 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 6767fff..8a16f85 100644
--- a/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php
+++ b/core/modules/views/tests/src/Kernel/Plugin/ExposedFormRenderTest.php
@@ -22,7 +22,7 @@ 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 c6f581a..891e013 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 19d5e95..4261ac9 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 208a6f0..599629a 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 223963e..c0b022b 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 3e3bbac..4c32ef7 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 d0683de..a3ae4ec 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 879f6d4..f78afc4 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 e4a0884..f3c1dc4 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 ace4204..5ea8089 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 dcd1859..1b21dfe 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 4b1cfc3..76253f2 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 7390214..ec2a25f 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 294bb0f..e82a546 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 4bbe402..c65b779 100644
--- a/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php
+++ b/core/modules/views/tests/src/Kernel/ViewsKernelTestBase.php
@@ -28,7 +28,7 @@
   /**
    * {@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/Wizard/WizardPluginBaseKernelTest.php b/core/modules/views/tests/src/Kernel/Wizard/WizardPluginBaseKernelTest.php
index beb7b48..29844b5 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 83f2f85..3f4ea02 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 32d1ae9..9ed2345 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 d74575f..41faa00 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 1e53c71..70f47a3 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 9dba450..1230c12 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 7291dc2..d88dd34 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 44724b4..778d1db 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 0822eb8..c45394b 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 18ada1b..d831d05 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 3182994..d24c628 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 ef493ff..0da216a 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 d2527d0..5ffd700 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 e797993..7cf4ed6 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 df3d030..96e61e2 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 df42d8e..1c6941d 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 7238ffa..d85d74a 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 684b91f..e20f555 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 3265e1a..fe8dd99 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 956ab9b..d4633e7 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 839fe3a..19b82d6 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 cabb48e..49a467e 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 c8d37f2..8feb4ab 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 JavascriptTestBase {
   /**
    * {@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 e48487a..8a2aae7 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 JavascriptTestBase {
   /**
    * {@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 32b1a40..5404a7c 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 JavascriptTestBase {
   /**
    * {@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 4cf51d5..c7235c1 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 JavascriptTestBase {
   /**
    * {@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 cab99bd..4d7a361 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 JavascriptTestBase {
   /**
    * {@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 3fb1167..f65ce2a 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 JavascriptTestBase {
   /**
    * {@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 e63bf22..6e0b696 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 0c2fe00..e36e296 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 b2e9807..3c1632b 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 db687cf..f906529 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 ce796a4..43c0765 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/WorkflowUiNoTypeTest.php b/core/modules/workflows/tests/src/Functional/WorkflowUiNoTypeTest.php
index 197386e..f2c2bc3 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 b15b240..29ae6d9 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 15d2728..501675d 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 f3f0b57..2f294fd 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 8d4edc9..13d8718 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 cd4e7ce..c70b859 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 c1070dc..bc6d270 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/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php b/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
index 7df92f2..01e5f86 100644
--- a/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
+++ b/core/profiles/testing/modules/drupal_system_listing_compatible_test/src/Tests/SystemListingCompatibleTest.php
@@ -20,7 +20,7 @@ class SystemListingCompatibleTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = ['drupal_system_listing_compatible_test'];
+  protected static $modules = ['drupal_system_listing_compatible_test'];
 
   /**
    * Use the Minimal profile.
diff --git a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
index e13ecfd..42a9226 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxCallbacksTest.php
@@ -14,7 +14,7 @@ class AjaxCallbacksTest extends JavascriptTestBase {
   /**
    * {@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/AjaxFormImageButtonTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
index 4811a35..7f96bae 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormImageButtonTest.php
@@ -14,7 +14,7 @@ class AjaxFormImageButtonTest extends JavascriptTestBase {
   /**
    * {@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 3d174b0..9590e99 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxFormPageCacheTest.php
@@ -14,7 +14,7 @@ class AjaxFormPageCacheTest extends JavascriptTestBase {
   /**
    * {@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 e059405..82e21224 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Ajax/AjaxTest.php
@@ -14,7 +14,7 @@ class AjaxTest extends JavascriptTestBase {
   /**
    * {@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/Core/Form/FormGroupingElementsTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php
index 92b3a73..cccab29 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 JavascriptTestBase {
    *
    * @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 bf2643d..52b685b 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/MachineNameTest.php
@@ -19,7 +19,7 @@ class MachineNameTest extends JavascriptTestBase {
    *
    * @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 fa2d541..77a8a4a 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 JavascriptTestBase {
   /**
    * {@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 19cf5a4..c6c472c 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Dialog/DialogPositionTest.php
@@ -14,7 +14,7 @@ class DialogPositionTest extends JavascriptTestBase {
   /**
    * {@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 511dee6..1b3a5c4 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/EntityReference/EntityReferenceAutocompleteWidgetTest.php
@@ -21,7 +21,7 @@ class EntityReferenceAutocompleteWidgetTest extends JavascriptTestBase {
   /**
    * {@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 36f6340..057b01c 100644
--- a/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Tests/JSWebAssertTest.php
@@ -17,7 +17,7 @@ class JSWebAssertTest extends JavascriptTestBase {
    *
    * @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/Breadcrumb/Breadcrumb404Test.php b/core/tests/Drupal/FunctionalTests/Breadcrumb/Breadcrumb404Test.php
index 7dcafbf..cbf6b98 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 882e6ed..ead448c 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'];
+  protected static $modules = ['test_page_test', 'form_test', 'system_test'];
 
   /**
    * 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 698a7d1..262f58d 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 8faf8c6..7259ac9 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 e8c8ae5..78d4024 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 0f17e64..864e16a 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/HttpKernel/CorsIntegrationTest.php b/core/tests/Drupal/FunctionalTests/HttpKernel/CorsIntegrationTest.php
index c874834..677df6f 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 d501f1d..eecf9e4 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 2f6b7cc..0f1bc3d 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/Routing/CaseInsensitivePathTest.php b/core/tests/Drupal/FunctionalTests/Routing/CaseInsensitivePathTest.php
index 3aaac14..1db8dbf 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/PathEncodedTest.php b/core/tests/Drupal/FunctionalTests/Routing/PathEncodedTest.php
index a8aee89..8332399 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/KernelTests/Component/Utility/SafeMarkupKernelTest.php b/core/tests/Drupal/KernelTests/Component/Utility/SafeMarkupKernelTest.php
index 8fab307..82545bc 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 6abb5cc..d54db5c 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 06881f2..f5d6b92 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/Asset/AttachedAssetsTest.php b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
index 1e1c6fd..c6f474b 100644
--- a/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
@@ -39,7 +39,7 @@ 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 4836e16..fd091a8 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 2fbe025..140621f 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 66005de..88f01b3 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 0ae0230..6cfce9e 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 0fefc39..99f14dd 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 358b925..4563bfe 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 17b6ae4..4c0f80b 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 2375487..f2a7c10 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 c52e3ea..3882e01 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 9f2a1a7..88a4c0d 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 84b4e42..ada7ce4 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 b69735e..83d130c 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 5a137b9..91c7f42 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 1cd9cb1..71d7d9c 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 021136d..a95ab7c 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 ce9a928..104ae7a 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 807152b..0c0089a 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 74bb798..851fd6a 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 c69f9fe..a25ef61 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRecreateTest.php
@@ -27,7 +27,7 @@ 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 cbb2e95..e2a417c 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
@@ -30,7 +30,7 @@ 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 59f9cb2..ca5f2fb 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 9d3989c..dfd18a0 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
@@ -28,7 +28,7 @@ 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 9e473c2..89bbc2a 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 5bf6f0e..e249bd3 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 a94123d..d88ab6a 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 b2ddaa3..7c662f4 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 6c568b8..67c280c 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 6c0bc1a..8c8fff8 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 62eff04..f1c034a 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 f06806c..082237d 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/SchemaCheckTraitTest.php b/core/tests/Drupal/KernelTests/Core/Config/SchemaCheckTraitTest.php
index a11bcb6..2a879d7 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 2674a3c..4518b727 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/DatabaseTestBase.php b/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
index 6fcfaa4..fb72d27 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/DatabaseTestBase.php
@@ -12,7 +12,7 @@
  */
 abstract class DatabaseTestBase extends KernelTestBase {
 
-  public static $modules = ['database_test'];
+  protected static $modules = ['database_test'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php b/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
index 129d50b..b078c7b 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/NextIdTest.php
@@ -15,7 +15,7 @@ class NextIdTest extends KernelTestBase {
    * The modules to enable.
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   protected function setUp() {
     parent::setUp();
diff --git a/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
index 66eed0a..97e5dba 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 cd3ec4a..ae67e14 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 036b385..a127447 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 b5b9ffd..12aa7ef 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 613ba4e..5af2c6d 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/ConfigEntityQueryTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ConfigEntityQueryTest.php
index 56050a7..39da2d0 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 aa0044b..d165e70 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 0f77535..43fb54b 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 5e25c90..dda9da2 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 687ceb7..39ec64d 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 99c99b0..8c82ce5 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 6da9bb3..ed29e37 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 b5bcd48..5efe4eb 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 8f945b3..e3bd777 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 ed30d4b..15fdc48 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 9b279a5..7b269c8 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/EntityDefinitionUpdateTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
index e2e4ae2..c4e8ad4 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php
@@ -45,7 +45,7 @@ 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 ec1a55c..823ebb4 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 11aeede..dbfc7d2 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 31b1f9e..41bc5ad 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityFieldTest.php
@@ -32,7 +32,7 @@ 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/EntityKernelTestBase.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityKernelTestBase.php
index f7108d5..71fba5d 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 570aa98..3bb82a7 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityLanguageTestBase.php
@@ -40,7 +40,7 @@
    */
   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/EntityLoadedRevisionTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityLoadedRevisionTest.php
index a3b99fe..ba6a660 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityLoadedRevisionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityLoadedRevisionTest.php
@@ -17,7 +17,7 @@ class EntityLoadedRevisionTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = [
+  protected static $modules = [
     'system',
     'entity_test',
     'language',
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityNonRevisionableTranslatableFieldTest.php
index 2160da9..bf0f590 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 b6362fb..c534606 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 0bb5b16..2a4bc3b 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryRelationshipTest.php
@@ -23,7 +23,7 @@ class EntityQueryRelationshipTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['taxonomy'];
+  protected static $modules = ['taxonomy'];
 
   /**
    * @var \Drupal\Core\Entity\Query\QueryFactory
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
index ebb3072..a8d2f5b 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityQueryTest.php
@@ -27,7 +27,7 @@ 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 cedf685..8c9bedc 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 b2c72b9..55e0210 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 b43b376..c461e95 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityRevisionTranslationTest.php
@@ -15,7 +15,7 @@ class EntityRevisionTranslationTest extends EntityKernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['language'];
+  protected static $modules = ['language'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypeConstraintValidatorTest.php
index 3671d6d..201ffa6 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 5e755d9..c513305 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
@@ -31,7 +31,7 @@ class EntityTypedDataDefinitionTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'text', 'node', 'user'];
+  protected static $modules = ['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 bf2a147..517d6a5 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityValidationTest.php
@@ -16,7 +16,7 @@ class EntityValidationTest extends EntityKernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['filter', 'text'];
+  protected static $modules = ['filter', 'text'];
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
index 7ff6caf..1fcab3c 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
@@ -23,7 +23,7 @@ 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 041b062..fb67f7c 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', 'user', 'system'];
+  protected static $modules = ['entity_test', 'field', 'user', 'system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
index 73b3254..2c7fdd2 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
@@ -18,7 +18,7 @@ class RevisionableContentEntityBaseTest extends KernelTestBase {
   /**
    * {@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 df9f4b1..321ec3b 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 3f182c9..2682e8f 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 96e469a..cfb9e0a 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 7d29a26..7eb3a3c 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 fa5a9a1..7a1b6a1 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 404c2f0..d36b95b 100644
--- a/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Field/Entity/BaseFieldOverrideTest.php
@@ -18,7 +18,7 @@ class BaseFieldOverrideTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = ['system'];
+  protected static $modules = ['system'];
 
   /**
    * {@inheritdoc}
diff --git a/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php b/core/tests/Drupal/KernelTests/Core/Field/FieldAccessTest.php
index f273029..ca7a66b 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 590a96c..df867f1 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 92612ae..c5b7477 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 05ac7c2..0e434a1 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 e41fb74..69a1a11 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 e3c68a7..e38b048 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 b13b92c..cf8b425 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 6be98df..dc9de90 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 f826d4d..91b1903 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 e41f87e..b8b257e 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 817da28..c5e2675 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 0bd546b..bd9b3fc 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 6c18b66..ee12b81 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 bdf66bd..07a93d3 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/Form/ExternalFormUrlTest.php b/core/tests/Drupal/KernelTests/Core/Form/ExternalFormUrlTest.php
index f3fbc4f..b0c8006 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 f6fb4f8..0958392 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 6d79f17..701c45f 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 29bbcff..393ec93 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 d283d9b..337d69d 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 26a1abe..64fb0e4 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 5852da1..9e6bd9c 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 875ca7a..9435f8a 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 9885005..c49a2a2 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 d0da913..47fbe2b 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 9bb7f54..6a50349 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/Path/AliasStorageTest.php b/core/tests/Drupal/KernelTests/Core/Path/AliasStorageTest.php
index d7b24b4..e9967f5 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 1ecd524..6ee6bae 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 37ac65a..ae5f631 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 5d57d57..6769268 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/ConditionTestDualUserTest.php
@@ -31,7 +31,7 @@ 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 7a69d2e..7ed9920 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 96c8bac..f1ca081 100644
--- a/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Plugin/Condition/OptionalContextConditionTest.php
@@ -18,7 +18,7 @@ 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 68b6eb7..41ed77c 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/ContextPluginTest.php b/core/tests/Drupal/KernelTests/Core/Plugin/ContextPluginTest.php
index a9ec4b8..6f113b7 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/PluginTestBase.php b/core/tests/Drupal/KernelTests/Core/Plugin/PluginTestBase.php
index ccc8236..18b836d 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 b4e122b..578b8b9 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 135c7aa..70081bc 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 906e74b..5d59f52 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 5966eaa..69a5b80 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 91061ca..1d98ff4 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 a64b553..c3a0342 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'];
+  protected static $modules = ['system', 'common_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 2b59933..d1fd158 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 ea6a9c2..0a67f85 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 34c6d58..7a8fcf4 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 a791454..ca663d4 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 ed59f2f..8ce2808 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/RouteProviderTest.php
@@ -36,7 +36,7 @@ class RouteProviderTest extends KernelTestBase {
   /**
    * Modules to enable.
    */
-  public static $modules = ['url_alter_test', 'system'];
+  protected static $modules = ['url_alter_test', 'system'];
 
   /**
    * 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 053db79..8213800 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 970ea04..0411f5f 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 748e2bb..da7a2bf 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/Theme/ImageTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ImageTest.php
index 72cecce..e005cc3 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 294c8dc..b110c29 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 a20798e..ca49e03 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 a71c3fe..fafe93b 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 40d31e6..8089b79 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 8a79a9e..1d85402 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 61f6475..d41b55b 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ThemeInstallerTest.php
@@ -18,7 +18,7 @@ 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 c44cc1c..d8ab19a 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 a077c25..6b06265 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 5d6f61f..dffca33 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php
@@ -21,7 +21,7 @@ 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 dbdf351..319d021 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 7af10f5..a638169 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 e3e3fae..d795a6e 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 a724623..9a1527b 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 16452d0..aa483c8 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 8e17422..0c5363f 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 c7eb3b2..f4369ed 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}