25 files declare their use of CKEditor5

AddedStylesheetsTest.php in core/modules/ckeditor5/tests/src/Functional/AddedStylesheetsTest.php
ckeditor5.module in core/modules/ckeditor5/ckeditor5.module
CKEditor5DialogTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/CKEditor5DialogTest.php
CKEditor5MarkupTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/CKEditor5MarkupTest.php
CKEditor5Test.php in core/modules/ckeditor5/tests/src/Unit/CKEditor5Test.php
CKEditor5Test.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/CKEditor5Test.php
CKEditor5ToolbarTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/CKEditor5ToolbarTest.php
CKEditor5UpdateImageToolbarItemTest.php in core/modules/ckeditor5/tests/src/Functional/Update/CKEditor5UpdateImageToolbarItemTest.php
CKEditor5ValidationTestTrait.php in core/modules/ckeditor5/tests/src/Kernel/CKEditor5ValidationTestTrait.php
DemoUmamiProfileTest.php in core/profiles/demo_umami/tests/src/Functional/DemoUmamiProfileTest.php
EmphasisTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/EmphasisTest.php
ImageTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/ImageTest.php
ImageUrlTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/ImageUrlTest.php
MediaEntityMetadataApiTest.php in core/modules/ckeditor5/tests/src/Functional/MediaEntityMetadataApiTest.php
MediaLibraryTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaLibraryTest.php
MediaLinkabilityTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaLinkabilityTest.php
MediaTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaTest.php
MediaTestBase.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaTestBase.php
SourceEditingEmptyElementTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/SourceEditingEmptyElementTest.php
SourceEditingTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/SourceEditingTest.php
SourceEditingTestBase.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/SourceEditingTestBase.php
StandardTestTrait.php in core/profiles/standard/tests/src/Traits/StandardTestTrait.php
StyleTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/StyleTest.php
TableTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/TableTest.php
WildcardHtmlSupportTest.php in core/modules/ckeditor5/tests/src/Kernel/WildcardHtmlSupportTest.php

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