100 files declare their use of FormattableMarkup

AssertContentTrait.php in core/tests/Drupal/KernelTests/AssertContentTrait.php
AssertMailTrait.php in core/lib/Drupal/Core/Test/AssertMailTrait.php
BanMiddleware.php in core/modules/ban/src/BanMiddleware.php
BasicAuth.php in core/modules/basic_auth/src/Authentication/Provider/BasicAuth.php
BookJavascriptTest.php in core/modules/book/tests/src/FunctionalJavascript/BookJavascriptTest.php
BrokenHandlerTrait.php in core/modules/views/src/Plugin/views/BrokenHandlerTrait.php
CommentAdminTest.php in core/modules/comment/tests/src/Functional/CommentAdminTest.php
CommentPagerTest.php in core/modules/comment/tests/src/Functional/CommentPagerTest.php
CommentTestBase.php in core/modules/comment/tests/src/Functional/CommentTestBase.php
ConfigEntityTest.php in core/modules/config/tests/src/Functional/ConfigEntityTest.php
ConfigImporterMissingContentTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigImporterMissingContentTest.php
ConfigImporterTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigImporterTest.php
ConfigImportRenameValidationTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigImportRenameValidationTest.php
ConfigSchemaChecker.php in core/lib/Drupal/Core/Config/Development/ConfigSchemaChecker.php
ConfigTestForm.php in core/modules/config/tests/config_test/src/ConfigTestForm.php
ContactPersonalTest.php in core/modules/contact/tests/src/Functional/ContactPersonalTest.php
ContentEntityBase.php in core/lib/Drupal/Core/Entity/ContentEntityBase.php
ContentTranslationWorkflowsTest.php in core/modules/content_translation/tests/src/Functional/ContentTranslationWorkflowsTest.php
ContentTypeCreationTrait.php in core/modules/node/tests/src/Traits/ContentTypeCreationTrait.php
ContextualLinksPlaceholder.php in core/modules/contextual/src/Element/ContextualLinksPlaceholder.php
CurrentThemeConditionTest.php in core/tests/Drupal/KernelTests/Core/Plugin/Condition/CurrentThemeConditionTest.php
DateTimeFieldTest.php in core/modules/datetime/tests/src/Functional/DateTimeFieldTest.php
DbLogController.php in core/modules/dblog/src/Controller/DbLogController.php
DblogMessage.php in core/modules/dblog/src/Plugin/views/field/DblogMessage.php
DbLogTest.php in core/modules/dblog/tests/src/Functional/DbLogTest.php
DisplayApiTest.php in core/modules/field/tests/src/Kernel/DisplayApiTest.php
DisplayPluginBase.php in core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
DisplayTest.php in core/modules/views/tests/src/Functional/Plugin/DisplayTest.php
EditorAdminTest.php in core/modules/editor/tests/src/Functional/EditorAdminTest.php
EntityAccessControlHandlerTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityAccessControlHandlerTest.php
EntityOperationsTest.php in core/modules/system/tests/src/Functional/Entity/EntityOperationsTest.php
EntityReferenceAdminTest.php in core/modules/field/tests/src/FunctionalJavascript/EntityReference/EntityReferenceAdminTest.php
EntityReferenceItem.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
EntityReferenceItemTest.php in core/modules/field/tests/src/Kernel/EntityReference/EntityReferenceItemTest.php
entity_test.module in core/modules/system/tests/modules/entity_test/entity_test.module
Test module for the entity API providing several entity types for testing.
Error.php in core/lib/Drupal/Core/Utility/Error.php
ErrorHandlerTest.php in core/modules/system/tests/src/Functional/System/ErrorHandlerTest.php
errors.inc in core/includes/errors.inc
Functions for error handling.
FieldKernelTestBase.php in core/modules/field/tests/src/Kernel/FieldKernelTestBase.php
FieldWidgetConstraintValidatorTest.php in core/tests/Drupal/KernelTests/Core/Entity/FieldWidgetConstraintValidatorTest.php
FileFieldTestBase.php in core/modules/file/tests/src/Functional/FileFieldTestBase.php
FileManagedTestBase.php in core/modules/file/tests/src/Functional/FileManagedTestBase.php
FileManagedUnitTestBase.php in core/modules/file/tests/src/Kernel/FileManagedUnitTestBase.php
FilterTestPlaceholders.php in core/modules/filter/tests/filter_test/src/Plugin/Filter/FilterTestPlaceholders.php
FinalExceptionSubscriber.php in core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php
FormattableMarkupKernelTest.php in core/tests/Drupal/KernelTests/Component/Render/FormattableMarkupKernelTest.php
FormattableMarkupTest.php in core/tests/Drupal/Tests/Component/Render/FormattableMarkupTest.php
FormElementsRenderTest.php in core/modules/system/tests/src/Kernel/Common/FormElementsRenderTest.php
FormTest.php in core/modules/system/tests/src/Functional/Form/FormTest.php
ForumBlockTest.php in core/modules/forum/tests/src/Functional/ForumBlockTest.php
FunctionsTest.php in core/modules/system/tests/src/Kernel/Theme/FunctionsTest.php
HelpTest.php in core/modules/help/tests/src/Functional/HelpTest.php
ImageToolkitOperationManager.php in core/lib/Drupal/Core/ImageToolkit/ImageToolkitOperationManager.php
LayoutBuilderDisableInteractionsTest.php in core/modules/layout_builder/tests/src/FunctionalJavascript/LayoutBuilderDisableInteractionsTest.php
LinearHistoryTest.php in core/tests/Drupal/Tests/Core/Config/Checkpoint/LinearHistoryTest.php
LogMessageParserTest.php in core/tests/Drupal/Tests/Core/Logger/LogMessageParserTest.php
MaintenanceMode.php in core/lib/Drupal/Core/Site/MaintenanceMode.php
MarkupInterfaceComparatorTest.php in core/tests/Drupal/KernelTests/Core/Test/Comparator/MarkupInterfaceComparatorTest.php
MediaLibraryWidget.php in core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php
ModuleTest.php in core/modules/views/tests/src/Kernel/ModuleTest.php
NodeTestBase.php in core/modules/node/tests/src/Functional/NodeTestBase.php
PlainTextOutputTest.php in core/tests/Drupal/Tests/Component/Render/PlainTextOutputTest.php
PluralVariants.php in core/modules/config_translation/src/FormElement/PluralVariants.php
PoStreamReader.php in core/lib/Drupal/Component/Gettext/PoStreamReader.php
PreExistingConfigException.php in core/lib/Drupal/Core/Config/PreExistingConfigException.php
Rearrange.php in core/modules/views_ui/src/Form/Ajax/Rearrange.php
ReorderDisplays.php in core/modules/views_ui/src/Form/Ajax/ReorderDisplays.php
RevisionDeleteFormTest.php in core/tests/Drupal/FunctionalTests/Entity/RevisionDeleteFormTest.php
RevisionRevertFormTest.php in core/tests/Drupal/FunctionalTests/Entity/RevisionRevertFormTest.php
SaveUploadTest.php in core/modules/file/tests/src/Functional/SaveUploadTest.php
SearchExtraTypeSearch.php in core/modules/search/tests/modules/search_extra_type/src/Plugin/Search/SearchExtraTypeSearch.php
SessionTestForm.php in core/modules/system/tests/modules/session_test/src/Form/SessionTestForm.php
shortcut.module in core/modules/shortcut/shortcut.module
Allows users to manage customizable lists of shortcut links.
ShortcutLinksTest.php in core/modules/shortcut/tests/src/Functional/ShortcutLinksTest.php
SmartDefaultSettings.php in core/modules/ckeditor5/src/SmartDefaultSettings.php
SmartDefaultSettingsTest.php in core/modules/ckeditor5/tests/src/Kernel/SmartDefaultSettingsTest.php
SortDateTest.php in core/modules/views/tests/src/Kernel/Handler/SortDateTest.php
StringFieldTest.php in core/modules/field/tests/src/Functional/FunctionalString/StringFieldTest.php
SymfonyMailerTest.php in core/tests/Drupal/Tests/Core/Mail/Plugin/Mail/SymfonyMailerTest.php
TableSort.php in core/lib/Drupal/Core/Utility/TableSort.php
TermValidationTest.php in core/modules/taxonomy/tests/src/Kernel/TermValidationTest.php
TestControllers.php in core/modules/system/tests/modules/menu_test/src/TestControllers.php
TimestampAgoFormatter.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampAgoFormatter.php
TimestampFormatter.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/TimestampFormatter.php
TimestampFormatterTest.php in core/modules/field/tests/src/Kernel/Timestamp/TimestampFormatterTest.php
TranslatableMarkup.php in core/lib/Drupal/Core/StringTranslation/TranslatableMarkup.php
TranslatableMarkupTest.php in core/tests/Drupal/Tests/Core/StringTranslation/TranslatableMarkupTest.php
TwigMarkupInterfaceTest.php in core/tests/Drupal/KernelTests/Core/Theme/TwigMarkupInterfaceTest.php
UncaughtExceptionTest.php in core/tests/Drupal/FunctionalTests/Bootstrap/UncaughtExceptionTest.php
UniqueFieldConstraintTest.php in core/tests/Drupal/KernelTests/Core/Validation/UniqueFieldConstraintTest.php
UnmetDependenciesException.php in core/lib/Drupal/Core/Config/UnmetDependenciesException.php
update_test_schema.install in core/modules/system/tests/modules/update_test_schema/update_test_schema.install
Update hooks and schema definition for the update_test_schema module.
UserRoleConditionTest.php in core/modules/user/tests/src/Kernel/Condition/UserRoleConditionTest.php
user_hooks_test.module in core/modules/user/tests/modules/user_hooks_test/user_hooks_test.module
Support module for user hooks testing.
ViewEditForm.php in core/modules/views_ui/src/ViewEditForm.php
ViewResultAssertionTrait.php in core/modules/views/src/Tests/ViewResultAssertionTrait.php
ViewsDataHelper.php in core/modules/views/src/ViewsDataHelper.php
ViewsIntegrationTest.php in core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php
views_ui.theme.inc in core/modules/views_ui/views_ui.theme.inc
Preprocessors and theme functions for the Views UI.
VocabularyUiTest.php in core/modules/taxonomy/tests/src/Functional/VocabularyUiTest.php

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