13 files declare their use of ConfigEntityBase

Block.php in core/modules/block/src/Entity/Block.php
ConfigEntityBaseUnitTest.php in core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityBaseUnitTest.php
ConfigEntityBaseWithPluginCollections.php in core/tests/Drupal/Tests/Core/Config/Entity/Fixtures/ConfigEntityBaseWithPluginCollections.php
ConfigEntityStorageTest.php in core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php
DateFormat.php in core/lib/Drupal/Core/Datetime/Entity/DateFormat.php
Editor.php in core/modules/editor/src/Entity/Editor.php
EntityDisplayBase.php in core/lib/Drupal/Core/Entity/EntityDisplayBase.php
EntityDisplayModeBase.php in core/lib/Drupal/Core/Entity/EntityDisplayModeBase.php
EntityLinkTest.php in core/tests/Drupal/Tests/Core/Entity/EntityLinkTest.php
FieldConfigBase.php in core/lib/Drupal/Core/Field/FieldConfigBase.php
ImageStyle.php in core/modules/image/src/Entity/ImageStyle.php
Role.php in core/modules/user/src/Entity/Role.php
TestConfigType.php in core/modules/system/tests/modules/module_installer_config_test/src/Entity/TestConfigType.php

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