12 files declare their use of ComplexDataInterface

ComplexDataConstraintValidator.php in drupal/core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/ComplexDataConstraintValidator.php: Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\ComplexDataConstraintValidator.
Context.php in drupal/core/lib/Drupal/Core/Plugin/Context/Context.php: Contains \Drupal\Core\Plugin\Context\Context.
DatabaseStorageControllerNG.php in drupal/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php: Contains \Drupal\Core\Entity\DatabaseStorageControllerNG.
EntityInterface.php in drupal/core/lib/Drupal/Core/Entity/EntityInterface.php: Contains \Drupal\Core\Entity\EntityInterface.
EntityTranslation.php in drupal/core/lib/Drupal/Core/Entity/Field/Type/EntityTranslation.php: Contains \Drupal\Core\Entity\Type\EntityTranslation.
EntityTranslationUITest.php in drupal/core/modules/translation_entity/lib/Drupal/translation_entity/Tests/EntityTranslationUITest.php: Definition of Drupal\entity\Tests\EntityTranslationUITest.
EntityWrapper.php in drupal/core/lib/Drupal/Core/Entity/Field/Type/EntityWrapper.php: Contains \Drupal\Core\Entity\Field\Type\EntityWrapper.
FieldItemInterface.php in drupal/core/lib/Drupal/Core/Entity/Field/FieldItemInterface.php: Contains \Drupal\Core\Entity\Field\FieldItemInterface.
Map.php in drupal/core/lib/Drupal/Core/TypedData/Type/Map.php: Contains \Drupal\Core\TypedData\Type\Map.
Mapping.php in drupal/core/lib/Drupal/Core/Config/Schema/Mapping.php: Contains \Drupal\Core\Config\Schema\Mapping.
MetadataFactory.php in drupal/core/lib/Drupal/Core/TypedData/Validation/MetadataFactory.php: Contains \Drupal\Core\TypedData\Validation\MetadataFactory.
PropertyContainerMetadata.php in drupal/core/lib/Drupal/Core/TypedData/Validation/PropertyContainerMetadata.php: Contains \Drupal\Core\TypedData\Validation\PropertyContainerMetadata.