All classes that implement RequiredFieldStorageDefinitionInterface in Drupal 9
- class \Drupal\Core\Field\BaseFieldDefinition implements FieldDefinitionInterface, FieldStorageDefinitionInterface, RequiredFieldStorageDefinitionInterface uses UnchangingCacheableDependencyTrait, FieldInputValueNormalizerTrait
- class \Drupal\Tests\migrate\Unit\Plugin\migrate\destination\BaseFieldDefinitionTest
- class \Drupal\entity_test\FieldStorageDefinition
- class \Drupal\field_inheritance\FieldStorageDefinition
- class \Drupal\opigno_certificate\FieldStorageDefinition