47 files declare their use of DefaultPluginManager

ActionManager.php in core/lib/Drupal/Core/Action/ActionManager.php
AggregatorPluginManager.php in core/modules/aggregator/src/Plugin/AggregatorPluginManager.php
ArchiverManager.php in core/lib/Drupal/Core/Archiver/ArchiverManager.php
BlockManager.php in core/lib/Drupal/Core/Block/BlockManager.php
BreakpointManager.php in core/modules/breakpoint/src/BreakpointManager.php
CategorizingPluginManagerTraitTest.php in core/tests/Drupal/Tests/Core/Plugin/CategorizingPluginManagerTraitTest.php
Contains \Drupal\Tests\Core\Plugin\CategorizingPluginManagerTraitTest.
CKEditorPluginManager.php in core/modules/ckeditor/src/CKEditorPluginManager.php
ConditionManager.php in core/lib/Drupal/Core/Condition/ConditionManager.php
ConfigMapperManager.php in core/modules/config_translation/src/ConfigMapperManager.php
ConstraintManager.php in core/lib/Drupal/Core/Validation/ConstraintManager.php
ContextualLinkManager.php in core/lib/Drupal/Core/Menu/ContextualLinkManager.php
DefaultsTestPluginManager.php in core/modules/system/tests/modules/plugin_test/src/Plugin/DefaultsTestPluginManager.php
EditorManager.php in core/modules/editor/src/Plugin/EditorManager.php
ElementInfoManager.php in core/lib/Drupal/Core/Render/ElementInfoManager.php
EntityTypeManager.php in core/lib/Drupal/Core/Entity/EntityTypeManager.php
FieldTypePluginManager.php in core/lib/Drupal/Core/Field/FieldTypePluginManager.php
FilterPluginManager.php in core/modules/filter/src/FilterPluginManager.php
FormatterPluginManager.php in core/lib/Drupal/Core/Field/FormatterPluginManager.php
HelpSectionManager.php in core/modules/help/src/HelpSectionManager.php
HelpTopicPluginManager.php in core/modules/help_topics/src/HelpTopicPluginManager.php
ImageEffectManager.php in core/modules/image/src/ImageEffectManager.php
ImageToolkitManager.php in core/lib/Drupal/Core/ImageToolkit/ImageToolkitManager.php
ImageToolkitOperationManager.php in core/lib/Drupal/Core/ImageToolkit/ImageToolkitOperationManager.php
InPlaceEditorManager.php in core/modules/quickedit/src/Plugin/InPlaceEditorManager.php
LanguageNegotiationMethodManager.php in core/modules/language/src/LanguageNegotiationMethodManager.php
LayoutPluginManager.php in core/lib/Drupal/Core/Layout/LayoutPluginManager.php
LinkRelationTypeManager.php in core/lib/Drupal/Core/Http/LinkRelationTypeManager.php
LocalActionManager.php in core/lib/Drupal/Core/Menu/LocalActionManager.php
LocalTaskManager.php in core/lib/Drupal/Core/Menu/LocalTaskManager.php
MailManager.php in core/lib/Drupal/Core/Mail/MailManager.php
MediaSourceManager.php in core/modules/media/src/MediaSourceManager.php
MigratePluginManager.php in core/modules/migrate/src/Plugin/MigratePluginManager.php
MigrationPluginManager.php in core/modules/migrate/src/Plugin/MigrationPluginManager.php
PluginManager.php in core/modules/system/tests/modules/lazy_route_provider_install_test/src/PluginManager.php
QueueWorkerManager.php in core/lib/Drupal/Core/Queue/QueueWorkerManager.php
ResourcePluginManager.php in core/modules/rest/src/Plugin/Type/ResourcePluginManager.php
SearchPluginManager.php in core/modules/search/src/SearchPluginManager.php
SectionStorageManager.php in core/modules/layout_builder/src/SectionStorage/SectionStorageManager.php
SelectionPluginManager.php in core/lib/Drupal/Core/Entity/EntityReferenceSelection/SelectionPluginManager.php
TestPluginManager.php in core/tests/Drupal/Tests/Core/Plugin/TestPluginManager.php
TipPluginManager.php in core/modules/tour/src/TipPluginManager.php
TypedDataManager.php in core/lib/Drupal/Core/TypedData/TypedDataManager.php
VariantManager.php in core/lib/Drupal/Core/Display/VariantManager.php
ViewsHandlerManager.php in core/modules/views/src/Plugin/ViewsHandlerManager.php
ViewsPluginManager.php in core/modules/views/src/Plugin/ViewsPluginManager.php
WidgetPluginManager.php in core/lib/Drupal/Core/Field/WidgetPluginManager.php
WorkflowTypeManager.php in core/modules/workflows/src/WorkflowTypeManager.php

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