All classes that implement EntityFieldManagerInterface in Drupal 8
- class \Drupal\Core\Entity\EntityFieldManager implements EntityFieldManagerInterface uses UseCacheBackendTrait, StringTranslationTrait
- class \Drupal\Core\Entity\EntityManager implements \Symfony\Component\DependencyInjection\ContainerAwareInterface, EntityManagerInterface uses \Symfony\Component\DependencyInjection\ContainerAwareTrait
- class \Drupal\Tests\Core\Entity\TestEntityFieldManager