FieldConfigInterface

class \Drupal\Core\Field\Entity\BaseFieldOverride extends \Drupal\Core\Field\FieldConfigBase
class \Drupal\Core\Field\FieldConfigBase extends \Drupal\Core\Config\Entity\ConfigEntityBase implements \Drupal\Core\Field\FieldConfigInterface uses \Drupal\Core\Field\FieldInputValueNormalizerTrait
class \Drupal\field\Entity\FieldConfig extends \Drupal\Core\Field\FieldConfigBase implements \Drupal\field\FieldConfigInterface