40 files declare their use of Attribute

ActiveLinkResponseFilterTest.php in core/tests/Drupal/Tests/Core/EventSubscriber/ActiveLinkResponseFilterTest.php
AttributeHelperTest.php in core/tests/Drupal/Tests/Core/Template/AttributeHelperTest.php
AttributesTest.php in core/tests/Drupal/Tests/Core/Common/AttributesTest.php
AttributeTest.php in core/tests/Drupal/Tests/Core/Template/AttributeTest.php
book.module in core/modules/book/book.module
Allows users to create and organize related content in an outline.
BookManager.php in core/modules/book/src/BookManager.php
claro.theme in core/themes/claro/claro.theme
Functions to support theming in the Claro theme.
ComponentRenderTest.php in core/modules/sdc/tests/src/Kernel/ComponentRenderTest.php
ComponentRenderTest.php in core/tests/Drupal/KernelTests/Components/ComponentRenderTest.php
ComponentValidatorTest.php in core/modules/sdc/tests/src/Unit/ComponentValidatorTest.php
ComponentValidatorTest.php in core/tests/Drupal/Tests/Core/Theme/Component/ComponentValidatorTest.php
ContextualLinksPlaceholder.php in core/modules/contextual/src/Element/ContextualLinksPlaceholder.php
DisplayBlockTest.php in core/modules/block/tests/src/Functional/Views/DisplayBlockTest.php
file.module in core/modules/file/file.module
FileMediaFormatterBase.php in core/modules/file/src/Plugin/Field/FieldFormatter/FileMediaFormatterBase.php
filter.module in core/modules/filter/filter.module
form.inc in core/includes/form.inc
Functions for form and batch generation and processing.
HtmlTag.php in core/lib/Drupal/Core/Render/Element/HtmlTag.php
language.admin.inc in core/modules/language/language.admin.inc
layout_discovery.module in core/modules/layout_discovery/layout_discovery.module
Provides hook implementations for Layout Discovery.
LinkGenerator.php in core/lib/Drupal/Core/Utility/LinkGenerator.php
media.module in core/modules/media/media.module
media_library.module in core/modules/media_library/media_library.module
MenuLinkTree.php in core/lib/Drupal/Core/Menu/MenuLinkTree.php
MenuLinkTreeTest.php in core/modules/system/tests/src/Unit/Menu/MenuLinkTreeTest.php
node.module in core/modules/node/node.module
olivero.theme in core/themes/olivero/olivero.theme
Functions to support theming in the Olivero theme.
RendererTest.php in core/tests/Drupal/Tests/Core/Render/RendererTest.php
responsive_image.module in core/modules/responsive_image/responsive_image.module
system.admin.inc in core/modules/system/system.admin.inc
Admin page callbacks for the system module.
theme.inc in core/includes/theme.inc
The theme system, which controls the output of Drupal.
ThemeManager.php in core/lib/Drupal/Core/Theme/ThemeManager.php
toolbar.module in core/modules/toolbar/toolbar.module
Administration toolbar for quick access to top level administration items.
TwigExtension.php in core/modules/sdc/src/Twig/TwigExtension.php
TwigExtensionTest.php in core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
TwigSandboxTest.php in core/tests/Drupal/Tests/Core/Template/TwigSandboxTest.php
TwigThemeTestController.php in core/modules/system/tests/modules/twig_theme_test/src/TwigThemeTestController.php
update.report.inc in core/modules/update/update.report.inc
Code required only when rendering the available updates report.
views.theme.inc in core/modules/views/views.theme.inc
views_ui.theme.inc in core/modules/views_ui/views_ui.theme.inc
Preprocessors and theme functions for the Views UI.

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