.../Core/Config/Testing/ConfigSchemaChecker.php    |  8 +++++++
 core/modules/action/src/Tests/BulkFormTest.php     |  5 +++++
 .../action_bulk_test/action_bulk_test.info.yml     |  1 +
 core/modules/block/src/Tests/BlockUiTest.php       |  5 +++++
 .../block_test/config/schema/block_test.schema.yml |  7 ++++++
 .../ckeditor/src/Tests/CKEditorAdminTest.php       | 10 ++++++---
 .../ckeditor/src/Tests/CKEditorLoadingTest.php     |  1 -
 .../modules/config/schema/ckeditor_test.schema.yml |  7 ++++++
 core/modules/color/color.module                    | 24 +++++++++++++--------
 .../color/src/Tests/ColorConfigSchemaTest.php      |  7 +++---
 core/modules/color/src/Tests/ColorTest.php         |  5 +++++
 .../config/schema/color_test_theme.schema.yml      |  5 +++++
 .../comment/config/schema/comment.schema.yml       |  2 +-
 .../comment/src/Tests/CommentActionsTest.php       |  5 +++++
 core/modules/editor/src/Tests/EditorAdminTest.php  | 25 ++++++++++++----------
 .../modules/config/schema/editor_test.schema.yml   |  2 +-
 .../modules/src/Plugin/Editor/UnicornEditor.php    |  8 +++----
 core/modules/image/config/schema/image.schema.yml  |  4 ++++
 .../image/src/Tests/ImageDimensionsTest.php        |  5 +++++
 .../search/src/Tests/SearchTokenizerTest.php       | 10 +++++++--
 .../statistics/config/schema/statistics.schema.yml | 14 ++++++++++++
 .../statistics/src/Tests/StatisticsReportsTest.php |  5 +++++
 .../taxonomy/src/Tests/VocabularyCrudTest.php      | 10 +++++++++
 core/modules/tour/src/Tests/TourTest.php           |  5 +++++
 24 files changed, 145 insertions(+), 35 deletions(-)

diff --git a/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php b/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php
index db80944..ba9e048 100644
--- a/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php
+++ b/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Config\ConfigEvents;
 use Drupal\Core\Config\Schema\SchemaCheckTrait;
 use Drupal\Core\Config\Schema\SchemaIncompleteException;
+use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
@@ -62,7 +63,14 @@ public function __construct(TypedConfigManagerInterface $typed_manager) {
    *   Exception thrown when configuration does not match its schema.
    */
   public function onConfigSave(ConfigCrudEvent $event) {
+    // Only validate configuration if in the default collection. Other
+    // collections may have incomplete configuration (for example language
+    // overrides only). These are not valid in themselves.
     $saved_config = $event->getConfig();
+    if ($saved_config->getStorage()->getCollectionName() != StorageInterface::DEFAULT_COLLECTION) {
+      return;
+    }
+
     $name = $saved_config->getName();
     $data = $saved_config->get();
     $checksum = crc32(serialize($data));
diff --git a/core/modules/action/src/Tests/BulkFormTest.php b/core/modules/action/src/Tests/BulkFormTest.php
index 8fd634b..86c34d0 100644
--- a/core/modules/action/src/Tests/BulkFormTest.php
+++ b/core/modules/action/src/Tests/BulkFormTest.php
@@ -19,6 +19,11 @@
 class BulkFormTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to install.
    *
    * @var array
diff --git a/core/modules/action/tests/action_bulk_test/action_bulk_test.info.yml b/core/modules/action/tests/action_bulk_test/action_bulk_test.info.yml
index 296a33a..37b4285 100644
--- a/core/modules/action/tests/action_bulk_test/action_bulk_test.info.yml
+++ b/core/modules/action/tests/action_bulk_test/action_bulk_test.info.yml
@@ -7,3 +7,4 @@ core: 8.x
 dependencies:
   - action
   - views
+  - node
diff --git a/core/modules/block/src/Tests/BlockUiTest.php b/core/modules/block/src/Tests/BlockUiTest.php
index e03135f..0313443 100644
--- a/core/modules/block/src/Tests/BlockUiTest.php
+++ b/core/modules/block/src/Tests/BlockUiTest.php
@@ -17,6 +17,11 @@
 class BlockUiTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to install.
    *
    * @var array
diff --git a/core/modules/block/tests/modules/block_test/config/schema/block_test.schema.yml b/core/modules/block/tests/modules/block_test/config/schema/block_test.schema.yml
new file mode 100644
index 0000000..e0b13cb
--- /dev/null
+++ b/core/modules/block/tests/modules/block_test/config/schema/block_test.schema.yml
@@ -0,0 +1,7 @@
+block.settings.test_block_instantiation:
+  type: block_settings
+  label: 'Test block instantiation settings'
+  mapping:
+    display_message:
+      type: string
+      label: 'Message text'
diff --git a/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php b/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php
index d4c1372..2773509 100644
--- a/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php
+++ b/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php
@@ -19,6 +19,11 @@
 class CKEditorAdminTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array
@@ -154,8 +159,7 @@ function testExistingFormat() {
     $this->drupalGet('admin/config/content/formats/manage/filtered_html');
     $expected_settings['toolbar']['rows'][0][] = array(
       'name' => 'Action history',
-      'items' => array('Undo', '|', 'Redo'),
-      array('JustifyCenter')
+      'items' => array('Undo', '|', 'Redo', 'JustifyCenter'),
     );
     $edit = array(
       'editor[settings][toolbar][button_groups]' => json_encode($expected_settings['toolbar']['rows']),
@@ -186,7 +190,7 @@ function testExistingFormat() {
     $this->drupalGet('admin/config/content/formats/manage/filtered_html');
     $ultra_llama_mode_checkbox = $this->xpath('//input[@type="checkbox" and @name="editor[settings][plugins][llama_contextual_and_button][ultra_llama_mode]" and @checked="checked"]');
     $this->assertTrue(count($ultra_llama_mode_checkbox) === 1, 'The "Ultra llama mode" checkbox exists and is checked.');
-    $expected_settings['plugins']['llama_contextual_and_button']['ultra_llama_mode'] = 1;
+    $expected_settings['plugins']['llama_contextual_and_button']['ultra_llama_mode'] = TRUE;
     $editor = entity_load('editor', 'filtered_html');
     $this->assertTrue($editor instanceof Editor, 'An Editor config entity exists.');
     $this->assertIdentical($expected_settings, $editor->getSettings());
diff --git a/core/modules/ckeditor/src/Tests/CKEditorLoadingTest.php b/core/modules/ckeditor/src/Tests/CKEditorLoadingTest.php
index 37e047c..98d73af 100644
--- a/core/modules/ckeditor/src/Tests/CKEditorLoadingTest.php
+++ b/core/modules/ckeditor/src/Tests/CKEditorLoadingTest.php
@@ -127,7 +127,6 @@ function testLoading() {
     // configuration also results in modified CKEditor configuration, so we
     // don't test that here.
     \Drupal::service('module_installer')->install(array('ckeditor_test'));
-    $this->resetAll();
     $this->container->get('plugin.manager.ckeditor.plugin')->clearCachedDefinitions();
     $editor_settings = $editor->getSettings();
     $editor_settings['toolbar']['buttons'][0][] = 'Llama';
diff --git a/core/modules/ckeditor/tests/modules/config/schema/ckeditor_test.schema.yml b/core/modules/ckeditor/tests/modules/config/schema/ckeditor_test.schema.yml
new file mode 100644
index 0000000..e6734a7
--- /dev/null
+++ b/core/modules/ckeditor/tests/modules/config/schema/ckeditor_test.schema.yml
@@ -0,0 +1,7 @@
+ckeditor.plugin.llama_contextual_and_button:
+  type: mapping
+  label: 'Contextual Llama With Button'
+  mapping:
+    ultra_llama_mode:
+      type: boolean
+      label: 'Ultra llama mode'
diff --git a/core/modules/color/color.module b/core/modules/color/color.module
index e9cc0a6..390af48 100644
--- a/core/modules/color/color.module
+++ b/core/modules/color/color.module
@@ -60,7 +60,8 @@ function color_form_system_theme_settings_alter(&$form, FormStateInterface $form
     );
     $form['color'] += color_scheme_form($form, $form_state, $theme);
     $form['#validate'][] = 'color_scheme_form_validate';
-    $form['#submit'][] = 'color_scheme_form_submit';
+    // Ensure color submission happens first so we can unset extra values.
+    array_unshift($form['#submit'], 'color_scheme_form_submit');
   }
 }
 
@@ -337,21 +338,26 @@ function color_scheme_form_validate($form, FormStateInterface $form_state) {
  */
 function color_scheme_form_submit($form, FormStateInterface $form_state) {
 
-  // Get theme coloring info.
-  if (!$form_state->hasValue('info')) {
+  // Avoid color settings spilling over to theme settings.
+  $color_settings = array('theme', 'palette', 'scheme');
+  if ($form_state->hasValue('info')) {
+    $color_settings[] = 'info';
+  }
+  foreach ($color_settings as $setting_name) {
+    ${$setting_name} = $form_state->getValue($setting_name);
+    $form_state->unsetValue($setting_name);
+  }
+  if (!isset($info)) {
     return;
   }
-  $theme = $form_state->getValue('theme');
-  $info = $form_state->getValue('info');
 
   $config = \Drupal::config('color.theme.' . $theme);
 
   // Resolve palette.
-  $palette = $form_state->getValue('palette');
-  if ($form_state->getValue('scheme') != '') {
+  if ($scheme != '') {
     foreach ($palette as $key => $color) {
-      if (isset($info['schemes'][$form_state->getValue('scheme')]['colors'][$key])) {
-        $palette[$key] = $info['schemes'][$form_state->getValue('scheme')]['colors'][$key];
+      if (isset($info['schemes'][$scheme]['colors'][$key])) {
+        $palette[$key] = $info['schemes'][$scheme]['colors'][$key];
       }
     }
     $palette += $info['schemes']['default']['colors'];
diff --git a/core/modules/color/src/Tests/ColorConfigSchemaTest.php b/core/modules/color/src/Tests/ColorConfigSchemaTest.php
index bb1e03c..01f3646 100644
--- a/core/modules/color/src/Tests/ColorConfigSchemaTest.php
+++ b/core/modules/color/src/Tests/ColorConfigSchemaTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\color\Tests;
 
-use Drupal\config\Tests\SchemaCheckTestTrait;
 use Drupal\simpletest\WebTestBase;
 
 /**
@@ -17,7 +16,10 @@
  */
 class ColorConfigSchemaTest extends WebTestBase {
 
-  use SchemaCheckTestTrait;
+  /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
 
   /**
    * Modules to install.
@@ -53,7 +55,6 @@ function testValidColorConfigSchema() {
     $edit['scheme'] = '';
     $edit['palette[bg]'] = '#123456';
     $this->drupalPostForm($settings_path, $edit, t('Save configuration'));
-    $this->assertConfigSchema(\Drupal::service('config.typed'), 'color.theme.bartik', \Drupal::config('color.theme.bartik')->get());
   }
 
 }
diff --git a/core/modules/color/src/Tests/ColorTest.php b/core/modules/color/src/Tests/ColorTest.php
index 185faae..8adc7f2 100644
--- a/core/modules/color/src/Tests/ColorTest.php
+++ b/core/modules/color/src/Tests/ColorTest.php
@@ -18,6 +18,11 @@
 class ColorTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to install.
    *
    * @var array
diff --git a/core/modules/color/tests/modules/color_test/themes/color_test_theme/config/schema/color_test_theme.schema.yml b/core/modules/color/tests/modules/color_test/themes/color_test_theme/config/schema/color_test_theme.schema.yml
new file mode 100644
index 0000000..33c19d6
--- /dev/null
+++ b/core/modules/color/tests/modules/color_test/themes/color_test_theme/config/schema/color_test_theme.schema.yml
@@ -0,0 +1,5 @@
+# Schema for the configuration files of the Color test theme.
+
+color_test_theme.settings:
+  type: theme_settings
+  label: 'Color test theme settings'
diff --git a/core/modules/comment/config/schema/comment.schema.yml b/core/modules/comment/config/schema/comment.schema.yml
index afd6570..9dd0aa5 100644
--- a/core/modules/comment/config/schema/comment.schema.yml
+++ b/core/modules/comment/config/schema/comment.schema.yml
@@ -24,7 +24,7 @@ action.configuration.comment_unpublish_by_keyword_action:
   type: mapping
   label: 'Unpublish comment containing keyword(s) configuration'
   mapping:
-    keyword:
+    keywords:
       type: sequence
       label: 'Keywords'
       sequence:
diff --git a/core/modules/comment/src/Tests/CommentActionsTest.php b/core/modules/comment/src/Tests/CommentActionsTest.php
index a0b50d6..e5443c1 100644
--- a/core/modules/comment/src/Tests/CommentActionsTest.php
+++ b/core/modules/comment/src/Tests/CommentActionsTest.php
@@ -17,6 +17,11 @@
 class CommentActionsTest extends CommentTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to install.
    *
    * @var array
diff --git a/core/modules/editor/src/Tests/EditorAdminTest.php b/core/modules/editor/src/Tests/EditorAdminTest.php
index ab79287..8e6ebd1 100644
--- a/core/modules/editor/src/Tests/EditorAdminTest.php
+++ b/core/modules/editor/src/Tests/EditorAdminTest.php
@@ -17,6 +17,11 @@
 class EditorAdminTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array
@@ -79,9 +84,9 @@ public function testAddEditorToExistingFormat() {
     $this->drupalGet('admin/config/content/formats/manage/filtered_html');
     $edit = $this->selectUnicornEditor();
     // Configure Unicorn Editor's setting to another value.
-    $edit['editor[settings][foo]'] = 'baz';
+    $edit['editor[settings][ponies_too]'] = FALSE;
     $this->drupalPostForm(NULL, $edit, t('Save configuration'));
-    $this->verifyUnicornEditorConfiguration('filtered_html', 'baz');
+    $this->verifyUnicornEditorConfiguration('filtered_html', FALSE);
   }
 
   /**
@@ -106,8 +111,6 @@ public function testAddEditorToNewFormat() {
    */
   protected function enableUnicornEditor() {
     \Drupal::service('module_installer')->install(array('editor_test'));
-    $this->rebuildContainer();
-    $this->resetAll();
   }
 
   /**
@@ -135,8 +138,8 @@ protected function selectUnicornEditor() {
       'editor[editor]' => 'unicorn',
     );
     $this->drupalPostAjaxForm(NULL, $edit, 'editor_configure');
-    $unicorn_setting_foo = $this->xpath('//input[@name="editor[settings][foo]" and @type="text" and @value="bar"]');
-    $this->assertTrue(count($unicorn_setting_foo), "Unicorn Editor's settings form is present.");
+    $unicorn_setting = $this->xpath('//input[@name="editor[settings][ponies_too]" and @type="checkbox" and @checked]');
+    $this->assertTrue(count($unicorn_setting), "Unicorn Editor's settings form is present.");
 
     return $edit;
   }
@@ -146,15 +149,15 @@ protected function selectUnicornEditor() {
    *
    * @param string $format_id
    *   The format machine name.
-   * @param string $foo
-   *   The expected value of the foo setting.
+   * @param string $ponies_too
+   *   The expected value of the ponies_too setting.
    */
-  protected function verifyUnicornEditorConfiguration($format_id, $foo = 'bar') {
+  protected function verifyUnicornEditorConfiguration($format_id, $ponies_too = TRUE) {
     $editor = editor_load($format_id);
     $settings = $editor->getSettings();
     $this->assertIdentical($editor->getEditor(), 'unicorn', 'The text editor is configured correctly.');
-    $this->assertIdentical($settings['foo'], $foo, 'The text editor settings are stored correctly.');
-    $this->assertIdentical($settings['ponies_too'], true, 'The text editor defaults are retrieved correctly.');
+    debug($settings);
+    $this->assertIdentical($settings['ponies_too'], $ponies_too, 'The text editor settings are stored correctly.');
     $this->drupalGet('admin/config/content/formats/manage/'. $format_id);
     $select = $this->xpath('//select[@name="editor[editor]"]');
     $select_is_disabled = $this->xpath('//select[@name="editor[editor]" and @disabled="disabled"]');
diff --git a/core/modules/editor/tests/modules/config/schema/editor_test.schema.yml b/core/modules/editor/tests/modules/config/schema/editor_test.schema.yml
index 6900e2f..64d94f8 100644
--- a/core/modules/editor/tests/modules/config/schema/editor_test.schema.yml
+++ b/core/modules/editor/tests/modules/config/schema/editor_test.schema.yml
@@ -5,5 +5,5 @@ editor.settings.unicorn:
   label: 'Unicorn settings'
   mapping:
     ponies_too:
-      type: string
+      type: boolean
       label: 'Ponies too'
diff --git a/core/modules/editor/tests/modules/src/Plugin/Editor/UnicornEditor.php b/core/modules/editor/tests/modules/src/Plugin/Editor/UnicornEditor.php
index 49644e5..7539021 100644
--- a/core/modules/editor/tests/modules/src/Plugin/Editor/UnicornEditor.php
+++ b/core/modules/editor/tests/modules/src/Plugin/Editor/UnicornEditor.php
@@ -35,10 +35,10 @@ function getDefaultSettings() {
    * {@inheritdoc}
    */
   function settingsForm(array $form, FormStateInterface $form_state, EditorEntity $editor) {
-    $form['foo'] = array(
-      '#title' => t('Foo'),
-      '#type' => 'textfield',
-      '#default_value' => 'bar',
+    $form['ponies_too'] = array(
+      '#title' => t('Pony mode'),
+      '#type' => 'checkbox',
+      '#default_value' => TRUE,
     );
     return $form;
   }
diff --git a/core/modules/image/config/schema/image.schema.yml b/core/modules/image/config/schema/image.schema.yml
index 7da7c47..87f38f6 100644
--- a/core/modules/image/config/schema/image.schema.yml
+++ b/core/modules/image/config/schema/image.schema.yml
@@ -28,6 +28,10 @@ image.style.*:
       sequence:
         - type: image_style.third_party.[%key]
 
+image.effect.*:
+  type: mapping
+  label: 'Effect settings'
+
 image.effect.image_crop:
   type: image_size
   label: 'Image crop'
diff --git a/core/modules/image/src/Tests/ImageDimensionsTest.php b/core/modules/image/src/Tests/ImageDimensionsTest.php
index 4d6c76b..2b05757 100644
--- a/core/modules/image/src/Tests/ImageDimensionsTest.php
+++ b/core/modules/image/src/Tests/ImageDimensionsTest.php
@@ -17,6 +17,11 @@
 class ImageDimensionsTest extends WebTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array
diff --git a/core/modules/search/src/Tests/SearchTokenizerTest.php b/core/modules/search/src/Tests/SearchTokenizerTest.php
index 66777b3..b3361a9 100644
--- a/core/modules/search/src/Tests/SearchTokenizerTest.php
+++ b/core/modules/search/src/Tests/SearchTokenizerTest.php
@@ -14,6 +14,12 @@
  * @group search
  */
 class SearchTokenizerTest extends SearchTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
   /**
    * Verifies that strings of CJK characters are tokenized.
    *
@@ -114,8 +120,8 @@ function testNoTokenizer() {
     // Set the minimum word size to 1 (to split all CJK characters) and make
     // sure CJK tokenizing is turned on.
     \Drupal::config('search.settings')
-      ->set('minimum_word_size', 1)
-      ->set('overlap_cjk', TRUE)
+      ->set('index.minimum_word_size', 1)
+      ->set('index.overlap_cjk', TRUE)
       ->save();
     $this->refreshVariables();
 
diff --git a/core/modules/statistics/config/schema/statistics.schema.yml b/core/modules/statistics/config/schema/statistics.schema.yml
index 58f262d..51da9ab 100644
--- a/core/modules/statistics/config/schema/statistics.schema.yml
+++ b/core/modules/statistics/config/schema/statistics.schema.yml
@@ -34,3 +34,17 @@ statistics.settings:
             top_recent_limit:
               type: integer
               label: 'Number of most recent views to display'
+
+block.settings.statistics_popular_block:
+  type: block_settings
+  label: 'Popular content block settings'
+  mapping:
+    top_day_num:
+      type: integer
+      label: 'Number of day\s top views to display'
+    top_all_num:
+      type: integer
+      label: 'Number of all time views to display'
+    top_last_num:
+      type: integer
+      label: 'Number of most recent views to display'
diff --git a/core/modules/statistics/src/Tests/StatisticsReportsTest.php b/core/modules/statistics/src/Tests/StatisticsReportsTest.php
index e3218cf..ed8ba14 100644
--- a/core/modules/statistics/src/Tests/StatisticsReportsTest.php
+++ b/core/modules/statistics/src/Tests/StatisticsReportsTest.php
@@ -15,6 +15,11 @@
 class StatisticsReportsTest extends StatisticsTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Tests the "popular content" block.
    */
   function testPopularContentBlock() {
diff --git a/core/modules/taxonomy/src/Tests/VocabularyCrudTest.php b/core/modules/taxonomy/src/Tests/VocabularyCrudTest.php
index 6cc1678..f2f7b54 100644
--- a/core/modules/taxonomy/src/Tests/VocabularyCrudTest.php
+++ b/core/modules/taxonomy/src/Tests/VocabularyCrudTest.php
@@ -18,6 +18,11 @@
 class VocabularyCrudTest extends TaxonomyTestBase {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array
@@ -193,6 +198,11 @@ function testUninstallReinstall() {
     );
     entity_create('field_config', $field_definition)->save();
 
+    // Remove the third party setting from the memory copy of the vocabulary.
+    // We keep this invalid copy around while the taxonomy module is not even
+    // installed for testing below.
+    $this->vocabulary->unsetThirdPartySetting('taxonomy_crud', 'foo');
+
     require_once \Drupal::root() . '/core/includes/install.inc';
     $this->container->get('module_installer')->uninstall(array('taxonomy'));
     $this->container->get('module_installer')->install(array('taxonomy'));
diff --git a/core/modules/tour/src/Tests/TourTest.php b/core/modules/tour/src/Tests/TourTest.php
index 8ed261c..ee8ea7b 100644
--- a/core/modules/tour/src/Tests/TourTest.php
+++ b/core/modules/tour/src/Tests/TourTest.php
@@ -17,6 +17,11 @@
 class TourTest extends TourTestBasic {
 
   /**
+   * {@inheritdoc}
+   */
+  protected $strictConfigSchema = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array