88 files declare their use of Json

ActiveLinkResponseFilter.php in core/lib/Drupal/Core/EventSubscriber/ActiveLinkResponseFilter.php
ActiveLinkResponseFilterTest.php in core/tests/Drupal/Tests/Core/EventSubscriber/ActiveLinkResponseFilterTest.php
AssertContentTrait.php in core/tests/Drupal/KernelTests/AssertContentTrait.php
AttachedAssetsTest.php in core/tests/Drupal/KernelTests/Core/Asset/AttachedAssetsTest.php
BasicTest.php in core/modules/views/tests/src/Functional/Wizard/BasicTest.php
BigPipeTest.php in core/modules/big_pipe/tests/src/Functional/BigPipeTest.php
BlockLibraryController.php in core/modules/block/src/Controller/BlockLibraryController.php
BlockListBuilder.php in core/modules/block/src/BlockListBuilder.php
BrowserTestBase.php in core/tests/Drupal/Tests/BrowserTestBase.php
BrowserTestBaseTest.php in core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
CKEditorAdminTest.php in core/modules/ckeditor/tests/src/Functional/CKEditorAdminTest.php
CKEditorToolbarButtonTest.php in core/modules/ckeditor/tests/src/Functional/CKEditorToolbarButtonTest.php
CommentNewIndicatorTest.php in core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php
CommentRestExportTest.php in core/modules/comment/tests/src/Functional/Views/CommentRestExportTest.php
CommentTest.php in core/modules/jsonapi/tests/src/Functional/CommentTest.php
CommonCollectionFilterAccessTestPatternsTrait.php in core/modules/jsonapi/tests/src/Traits/CommonCollectionFilterAccessTestPatternsTrait.php
ConfigurableLanguageTest.php in core/modules/jsonapi/tests/src/Functional/ConfigurableLanguageTest.php
ContentModerationConfigureForm.php in core/modules/content_moderation/src/Form/ContentModerationConfigureForm.php
contextual.module in core/modules/contextual/contextual.module
Adds contextual links to perform actions related to elements on a page.
ContextualDynamicContextTest.php in core/modules/contextual/tests/src/Functional/ContextualDynamicContextTest.php
ContextualLinks.php in core/modules/contextual/src/Plugin/views/field/ContextualLinks.php
DbLogResourceTest.php in core/modules/dblog/tests/src/Functional/DbLogResourceTest.php
DisplayBlockTest.php in core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
EditorSecurityTest.php in core/modules/editor/tests/src/Functional/EditorSecurityTest.php
ElementsVerticalTabsTest.php in core/modules/system/tests/src/Functional/Form/ElementsVerticalTabsTest.php
EmailTest.php in core/modules/system/tests/src/Functional/Form/EmailTest.php
EntityAutocompleteTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityAutocompleteTest.php
EntityResource.php in core/modules/jsonapi/src/Controller/EntityResource.php
EntitySerializationTest.php in core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
EntryPointTest.php in core/modules/jsonapi/tests/src/Functional/EntryPointTest.php
ExternalNormalizersTest.php in core/modules/jsonapi/tests/src/Functional/ExternalNormalizersTest.php
FieldUITest.php in core/modules/views_ui/tests/src/Functional/FieldUITest.php
FileFieldWidgetTest.php in core/modules/file/tests/src/Functional/FileFieldWidgetTest.php
FileTest.php in core/modules/jsonapi/tests/src/Functional/FileTest.php
FileUploadTest.php in core/modules/jsonapi/tests/src/Functional/FileUploadTest.php
FormHelper.php in core/lib/Drupal/Core/Form/FormHelper.php
FormHelperTest.php in core/tests/Drupal/Tests/Core/Form/FormHelperTest.php
FormTest.php in core/modules/system/tests/src/Functional/Form/FormTest.php
FormTestFormStateValuesCleanForm.php in core/modules/system/tests/modules/form_test/src/Form/FormTestFormStateValuesCleanForm.php
FrameworkTest.php in core/modules/system/tests/src/Functional/Ajax/FrameworkTest.php
FunctionsTest.php in core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
HistoryTest.php in core/modules/history/tests/src/Functional/HistoryTest.php
InternalEntitiesTest.php in core/modules/jsonapi/tests/src/Functional/InternalEntitiesTest.php
JsCollectionRenderer.php in core/lib/Drupal/Core/Asset/JsCollectionRenderer.php
JsonApiDocumentTopLevelNormalizerTest.php in core/modules/jsonapi/tests/src/Kernel/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php
JsonApiFunctionalMultilingualTest.php in core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalMultilingualTest.php
JsonApiFunctionalTest.php in core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalTest.php
JsonApiRegressionTest.php in core/modules/jsonapi/tests/src/Functional/JsonApiRegressionTest.php
JsonTest.php in core/tests/Drupal/Tests/Component/Serialization/JsonTest.php
LanguageSelectElementTest.php in core/modules/system/tests/src/Functional/Form/LanguageSelectElementTest.php
LinkGenerator.php in core/lib/Drupal/Core/Utility/LinkGenerator.php
locale.module in core/modules/locale/locale.module
Enables the translation of the user interface to languages other than English.
media_library.module in core/modules/media_library/media_library.module
Contains hook implementations for the media_library module.
MenuLinkContentTest.php in core/modules/jsonapi/tests/src/Functional/MenuLinkContentTest.php
NodeRevisionsTest.php in core/modules/node/tests/src/Functional/NodeRevisionsTest.php
NodeTest.php in core/modules/jsonapi/tests/src/Functional/NodeTest.php
OEmbedTestTrait.php in core/modules/media/tests/src/Traits/OEmbedTestTrait.php
OffCanvasDialogTest.php in core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
PlaceBlockPageVariant.php in core/modules/block_place/src/Plugin/DisplayVariant/PlaceBlockPageVariant.php
ProviderRepository.php in core/modules/media/src/OEmbed/ProviderRepository.php
QuickEditCustomPipelineTest.php in core/modules/quickedit/tests/src/Functional/QuickEditCustomPipelineTest.php
QuickEditEndPointAccessTest.php in core/modules/quickedit/tests/src/Functional/QuickEditEndPointAccessTest.php
QuickEditImageControllerTest.php in core/modules/image/tests/src/Functional/QuickEditImageControllerTest.php
QuickEditIntegrationLoadingTest.php in core/modules/editor/tests/src/Functional/QuickEditIntegrationLoadingTest.php
QuickEditIntegrationTest.php in core/modules/editor/tests/src/Kernel/QuickEditIntegrationTest.php
RenderWebTest.php in core/modules/system/tests/src/Functional/Common/RenderWebTest.php
RequestHandlerTest.php in core/modules/rest/tests/src/Kernel/RequestHandlerTest.php
ResourceFetcher.php in core/modules/media/src/OEmbed/ResourceFetcher.php
ResourceResponseSubscriberTest.php in core/modules/rest/tests/src/Unit/EventSubscriber/ResourceResponseSubscriberTest.php
ResourceResponseTestTrait.php in core/modules/jsonapi/tests/src/Functional/ResourceResponseTestTrait.php
ResourceResponseValidator.php in core/modules/jsonapi/src/EventSubscriber/ResourceResponseValidator.php
ResourceTestBase.php in core/modules/jsonapi/tests/src/Functional/ResourceTestBase.php
ResponseTest.php in core/modules/system/tests/src/Functional/Form/ResponseTest.php
SelectionTest.php in core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
ShortcutTest.php in core/modules/jsonapi/tests/src/Functional/ShortcutTest.php
StateValuesCleanTest.php in core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
StyleSerializerTest.php in core/modules/rest/tests/src/Functional/Views/StyleSerializerTest.php
TermAutocompleteTest.php in core/modules/taxonomy/tests/src/Functional/TermAutocompleteTest.php
TermTest.php in core/modules/jsonapi/tests/src/Functional/TermTest.php
TestController.php in core/modules/system/tests/modules/off_canvas_test/src/Controller/TestController.php
TestController.php in core/modules/views/tests/modules/views_test_modal/src/Controller/TestController.php
theme.inc in core/includes/theme.inc
The theme system, which controls the output of Drupal.
ThemeTest.php in core/modules/system/tests/src/Functional/Theme/ThemeTest.php
UrlTest.php in core/modules/system/tests/src/Functional/Form/UrlTest.php
UserTest.php in core/modules/jsonapi/tests/src/Functional/UserTest.php
WebTestBase.php in core/modules/simpletest/src/WebTestBase.php
WorkspaceListBuilder.php in core/modules/workspaces/src/WorkspaceListBuilder.php
workspaces.module in core/modules/workspaces/workspaces.module
Provides full-site preview functionality for content staging.

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