104 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
AjaxTestController.php in core/modules/system/tests/modules/ajax_test/src/Controller/AjaxTestController.php
AnnounceFetcher.php in core/modules/announcements_feed/src/AnnounceFetcher.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
CKEditor5.php in core/modules/ckeditor5/src/Plugin/Editor/CKEditor5.php
CKEditor5DialogTestController.php in core/modules/ckeditor5/tests/modules/ckeditor5_test/src/Controller/CKEditor5DialogTestController.php
CommentExtrasTest.php in core/modules/jsonapi/tests/src/Functional/CommentExtrasTest.php
CommentNewIndicatorTest.php in core/modules/comment/tests/src/Functional/CommentNewIndicatorTest.php
CommonCollectionFilterAccessTestPatternsTrait.php in core/modules/jsonapi/tests/src/Traits/CommonCollectionFilterAccessTestPatternsTrait.php
ConfigEntityListTest.php in core/modules/config/tests/src/Functional/ConfigEntityListTest.php
ConfigTranslationController.php in core/modules/config_translation/src/Controller/ConfigTranslationController.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
DisplayModeLocalAction.php in core/modules/field_ui/src/DisplayModeLocalAction.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
EntityDisplayModeController.php in core/modules/field_ui/src/Controller/EntityDisplayModeController.php
EntityDisplayModeListBuilder.php in core/modules/field_ui/src/EntityDisplayModeListBuilder.php
EntityForm.php in core/lib/Drupal/Core/Entity/EntityForm.php
EntityListBuilder.php in core/lib/Drupal/Core/Entity/EntityListBuilder.php
EntityResource.php in core/modules/jsonapi/src/Controller/EntityResource.php
EntitySerializationTest.php in core/modules/serialization/tests/src/Kernel/EntitySerializationTest.php
ExternalNormalizersTest.php in core/modules/jsonapi/tests/src/Functional/ExternalNormalizersTest.php
FieldConfigListBuilder.php in core/modules/field_ui/src/FieldConfigListBuilder.php
FieldUiLocalAction.php in core/modules/field_ui/src/Plugin/Derivative/FieldUiLocalAction.php
FieldUITest.php in core/modules/views_ui/tests/src/Functional/FieldUITest.php
FileFieldWidgetTest.php in core/modules/file/tests/src/Functional/FileFieldWidgetTest.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
FormTestVerticalTabsForm.php in core/modules/system/tests/modules/form_test/src/Form/FormTestVerticalTabsForm.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
GetDocumentFromResponseTrait.php in core/modules/jsonapi/tests/src/Traits/GetDocumentFromResponseTrait.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
JsonApiFunctionalDateFieldTest.php in core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalDateFieldTest.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
LazyBuilders.php in core/modules/announcements_feed/src/LazyBuilders.php
LinkGenerator.php in core/lib/Drupal/Core/Utility/LinkGenerator.php
LinksetControllerMultiLingualTest.php in core/modules/system/tests/src/Functional/Menu/LinksetControllerMultiLingualTest.php
LinksetControllerTest.php in core/modules/system/tests/src/Functional/Menu/LinksetControllerTest.php
LinksetControllerTestBase.php in core/modules/system/tests/src/Functional/Menu/LinksetControllerTestBase.php
locale.module in core/modules/locale/locale.module
Enables the translation of the user interface to languages other than English.
MenuLinkContentTest.php in core/modules/jsonapi/tests/src/Functional/MenuLinkContentTest.php
NodeActionsConfigurationTest.php in core/modules/action/tests/src/Functional/Node/NodeActionsConfigurationTest.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
PermissionsPerBundleTest.php in core/tests/Drupal/KernelTests/Core/Recipe/PermissionsPerBundleTest.php
ProviderRepository.php in core/modules/media/src/OEmbed/ProviderRepository.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
ResourceFetcherTest.php in core/modules/media/tests/src/Unit/ResourceFetcherTest.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
RowRenderCacheTest.php in core/modules/views/tests/src/Kernel/Plugin/RowRenderCacheTest.php
SecurityAdvisoriesFetcher.php in core/modules/system/src/SecurityAdvisories/SecurityAdvisoriesFetcher.php
SelectionTest.php in core/modules/field/tests/src/Functional/EntityReference/Views/SelectionTest.php
SourcePluginBase.php in core/modules/migrate/src/Plugin/migrate/source/SourcePluginBase.php
StateValuesCleanTest.php in core/modules/system/tests/src/Functional/Form/StateValuesCleanTest.php
StyleSerializerEntityTest.php in core/modules/rest/tests/src/Functional/Views/StyleSerializerEntityTest.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/views/tests/modules/views_test_modal/src/Controller/TestController.php
TestController.php in core/modules/system/tests/modules/dialog_renderer_test/src/Controller/TestController.php
TestController.php in core/modules/system/tests/modules/off_canvas_test/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
TimestampFormatter.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php
TimestampFormatterWithTimeDiffTest.php in core/tests/Drupal/FunctionalJavascriptTests/Core/Field/TimestampFormatterWithTimeDiffTest.php
ToolbarStoredStateTest.php in core/modules/toolbar/tests/src/FunctionalJavascript/ToolbarStoredStateTest.php
TwigExtensionTest.php in core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
UrlTest.php in core/modules/system/tests/src/Functional/Form/UrlTest.php
UserTest.php in core/modules/jsonapi/tests/src/Functional/UserTest.php
WorkspaceListBuilder.php in core/modules/workspaces/src/WorkspaceListBuilder.php
WorkspacesLazyBuilders.php in core/modules/workspaces/src/WorkspacesLazyBuilders.php

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