25 files declare their use of MediaTypeCreationTrait

ContentEntityTest.php in core/modules/migrate_drupal/tests/src/Kernel/Plugin/migrate/source/ContentEntityTest.php
ContentImportTest.php in core/tests/Drupal/FunctionalTests/DefaultContent/ContentImportTest.php
ContentModerationTest.php in core/modules/media_library/tests/src/FunctionalJavascript/ContentModerationTest.php
EntityQueryAccessTest.php in core/modules/views/tests/src/Functional/Entity/EntityQueryAccessTest.php
EntityReferenceSelectionAccessTest.php in core/modules/system/tests/src/Kernel/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
JSTranslationTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/JSTranslationTest.php
MediaCacheTagsTest.php in core/modules/media/tests/src/Functional/MediaCacheTagsTest.php
MediaEmbedFilterTestBase.php in core/modules/media/tests/src/Kernel/MediaEmbedFilterTestBase.php
MediaEntityMetadataApiTest.php in core/modules/ckeditor5/tests/src/Functional/MediaEntityMetadataApiTest.php
MediaFunctionalTestBase.php in core/modules/media/tests/src/Functional/MediaFunctionalTestBase.php
MediaJavascriptTestBase.php in core/modules/media/tests/src/FunctionalJavascript/MediaJavascriptTestBase.php
MediaKernelTestBase.php in core/modules/media/tests/src/Kernel/MediaKernelTestBase.php
MediaLibraryAccessTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryAccessTest.php
MediaLibraryAddFormTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryAddFormTest.php
MediaLibraryDisplayModeTest.php in core/modules/media_library/tests/src/Functional/MediaLibraryDisplayModeTest.php
MediaLibraryStateTest.php in core/modules/media_library/tests/src/Kernel/MediaLibraryStateTest.php
MediaLibraryTest.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaLibraryTest.php
MediaMappingsConstraintValidatorTest.php in core/modules/media/tests/src/Kernel/MediaMappingsConstraintValidatorTest.php
MediaTestBase.php in core/modules/ckeditor5/tests/src/FunctionalJavascript/MediaTestBase.php
MediaTranslationUITest.php in core/modules/media/tests/src/Functional/MediaTranslationUITest.php
MediaTypeValidationTest.php in core/modules/media/tests/src/Kernel/MediaTypeValidationTest.php
OEmbedResourceConstraintValidatorTest.php in core/modules/media/tests/src/Kernel/OEmbedResourceConstraintValidatorTest.php
PermissionsPerBundleTest.php in core/tests/Drupal/KernelTests/Core/Recipe/PermissionsPerBundleTest.php
RevisionUserTest.php in core/modules/media/tests/src/Kernel/Views/RevisionUserTest.php
TranslationsTest.php in core/modules/media_library/tests/src/FunctionalJavascript/TranslationsTest.php

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