Expanded class hierarchy of NullIncludedData in Drupal 9
- class \Drupal\jsonapi\JsonApiResource\Data implements \Drupal\jsonapi\JsonApiResource\IteratorAggregate, \Drupal\jsonapi\JsonApiResource\Countable
- class \Drupal\jsonapi\JsonApiResource\RelationshipData
- class \Drupal\jsonapi\JsonApiResource\ResourceObjectData implements TopLevelDataInterface
- class \Drupal\jsonapi\JsonApiResource\IncludedData
- class \Drupal\jsonapi\JsonApiResource\NullIncludedData
- class \Drupal\jsonapi\JsonApiResource\OmittedData
- class \Drupal\jsonapi\JsonApiResource\IncludedData