50 files declare their use of Xss

AggregatorController.php in core/modules/aggregator/src/Controller/AggregatorController.php
AlterTest.php in core/modules/system/tests/src/Functional/Form/AlterTest.php
AreaTest.php in core/modules/views/tests/src/Functional/Handler/AreaTest.php
AssertContentTrait.php in core/tests/Drupal/KernelTests/AssertContentTrait.php
AssertLegacyTrait.php in core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
Boolean.php in core/modules/views/src/Plugin/views/field/Boolean.php
Custom.php in core/modules/views/src/Plugin/views/field/Custom.php
DbLogController.php in core/modules/dblog/src/Controller/DbLogController.php
DisplayTest.php in core/modules/views/tests/modules/views_test_data/src/Plugin/views/display/DisplayTest.php
EntityField.php in core/modules/views/src/Plugin/views/field/EntityField.php
EntityReference.php in core/modules/views/src/Plugin/views/style/EntityReference.php
Error.php in core/lib/Drupal/Core/Utility/Error.php
errors.inc in core/includes/errors.inc
Functions for error handling.
FieldCustomTest.php in core/modules/views/tests/src/Kernel/Handler/FieldCustomTest.php
FieldFilteredMarkup.php in core/lib/Drupal/Core/Field/FieldFilteredMarkup.php
FieldPluginBase.php in core/modules/views/src/Plugin/views/field/FieldPluginBase.php
FilterHtml.php in core/modules/filter/src/Plugin/Filter/FilterHtml.php
FilterTestRestrictTagsAndAttributes.php in core/modules/filter/tests/filter_test/src/Plugin/Filter/FilterTestRestrictTagsAndAttributes.php
HandlerBase.php in core/modules/views/src/Plugin/views/HandlerBase.php
HtmlTag.php in core/lib/Drupal/Core/Render/Element/HtmlTag.php
IntegrationTest.php in core/modules/aggregator/tests/src/Kernel/Views/IntegrationTest.php
locale.module in core/modules/locale/locale.module
Enables the translation of the user interface to languages other than English.
MailFormatHelper.php in core/lib/Drupal/Core/Mail/MailFormatHelper.php
MenuController.php in core/modules/menu_ui/src/Controller/MenuController.php
node.api.php in core/modules/node/node.api.php
Hooks specific to the Node module.
node.module in core/modules/node/node.module
The core module that allows content to be submitted to the site.
NodeController.php in core/modules/node/src/Controller/NodeController.php
Page.php in core/modules/views/src/Plugin/views/display/Page.php
PageTitleTest.php in core/modules/system/tests/src/Functional/System/PageTitleTest.php
PluginBase.php in core/modules/views/src/Plugin/views/PluginBase.php
Renderer.php in core/lib/Drupal/Core/Render/Renderer.php
Standard.php in core/modules/editor/src/EditorXssFilter/Standard.php
StylePluginBase.php in core/modules/views/src/Plugin/views/style/StylePluginBase.php
TaxonomyController.php in core/modules/taxonomy/src/Controller/TaxonomyController.php
TextCustom.php in core/modules/views/src/Plugin/views/area/TextCustom.php
ThemeSuggestionsAlterTest.php in core/modules/system/tests/src/Functional/Theme/ThemeSuggestionsAlterTest.php
TokenizeAreaPluginBase.php in core/modules/views/src/Plugin/views/area/TokenizeAreaPluginBase.php
TokenReplaceKernelTest.php in core/modules/system/tests/src/Kernel/Token/TokenReplaceKernelTest.php
UserController.php in core/modules/user/src/Controller/UserController.php
ViewExecutableTest.php in core/modules/views/tests/src/Kernel/ViewExecutableTest.php
ViewPageController.php in core/modules/views/src/Routing/ViewPageController.php
views.theme.inc in core/modules/views/views.theme.inc
Preprocessors and helper functions to make theming easier.
ViewsBlock.php in core/modules/views/src/Plugin/Block/ViewsBlock.php
ViewsExposedFilterBlock.php in core/modules/views/src/Plugin/Block/ViewsExposedFilterBlock.php
ViewsIntegrationTest.php in core/modules/dblog/tests/src/Kernel/Views/ViewsIntegrationTest.php
ViewsSelection.php in core/modules/views/src/Plugin/EntityReferenceSelection/ViewsSelection.php
views_ui.module in core/modules/views_ui/views_ui.module
Provide structure for the administrative interface to Views.
ViewTranslationTest.php in core/modules/views/tests/src/Functional/ViewTranslationTest.php
ViewUI.php in core/modules/views_ui/src/ViewUI.php
XssTest.php in core/tests/Drupal/Tests/Component/Utility/XssTest.php

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