26 files declare their use of ConfigEntityInterface

AdminPathConfigEntityConverter.php in core/lib/Drupal/Core/ParamConverter/AdminPathConfigEntityConverter.php
BlockValidationTest.php in core/modules/block/tests/src/Kernel/BlockValidationTest.php
ConfigEntityMapperInterface.php in core/modules/config_translation/src/ConfigEntityMapperInterface.php
ConfigEntityStorageTest.php in core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php
ConfigEntityValidationTestBase.php in core/tests/Drupal/KernelTests/Core/Config/ConfigEntityValidationTestBase.php
ConfigManager.php in core/lib/Drupal/Core/Config/ConfigManager.php
DateFormat.php in core/lib/Drupal/Core/Datetime/Entity/DateFormat.php
DateFormatInterface.php in core/lib/Drupal/Core/Datetime/DateFormatInterface.php
EntityDeleteForm.php in core/lib/Drupal/Core/Entity/EntityDeleteForm.php
EntityDeriver.php in core/lib/Drupal/Core/Entity/Plugin/DataType/Deriver/EntityDeriver.php
EntityDisplayBase.php in core/lib/Drupal/Core/Entity/EntityDisplayBase.php
EntityDisplayInterface.php in core/lib/Drupal/Core/Entity/Display/EntityDisplayInterface.php
EntityDisplayModeBase.php in core/lib/Drupal/Core/Entity/EntityDisplayModeBase.php
EntityDisplayModeInterface.php in core/lib/Drupal/Core/Entity/EntityDisplayModeInterface.php
EntityMethod.php in core/lib/Drupal/Core/Config/Action/Plugin/ConfigAction/EntityMethod.php
EntityTypedDataDefinitionTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityTypedDataDefinitionTest.php
EntityTypeTest.php in core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php
Exists.php in core/lib/Drupal/Core/Config/Action/Exists.php
FieldConfigInterface.php in core/lib/Drupal/Core/Field/FieldConfigInterface.php
ImmutablePropertiesConstraintValidator.php in core/lib/Drupal/Core/Entity/Plugin/Validation/Constraint/ImmutablePropertiesConstraintValidator.php
ImmutablePropertiesConstraintValidatorTest.php in core/tests/Drupal/KernelTests/Core/Entity/ImmutablePropertiesConstraintValidatorTest.php
KeyValueEntityStorageTest.php in core/tests/Drupal/Tests/Core/Entity/KeyValueStore/KeyValueEntityStorageTest.php
RequiredConfigDependenciesConstraintValidator.php in core/lib/Drupal/Core/Config/Plugin/Validation/Constraint/RequiredConfigDependenciesConstraintValidator.php
RevisionableEntityBundleInterface.php in core/lib/Drupal/Core/Entity/RevisionableEntityBundleInterface.php
RoleInterface.php in core/modules/user/src/RoleInterface.php
SchemaCheckTrait.php in core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php

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