EntityReferenceFieldItemListInterface

class \Drupal\Core\Field\EntityReferenceFieldItemList extends \Drupal\Core\Field\EntityReferenceFieldItemListInterface implements \Drupal\Core\Field\FieldItemList
class \Drupal\entity_test\Plugin\Field\ComputedReferenceTestFieldItemList uses \Drupal\Core\TypedData\ComputedItemListTrait implements \Drupal\Core\Field\EntityReferenceFieldItemList
class \Drupal\file\Plugin\Field\FieldType\FileFieldItemList implements \Drupal\Core\Field\EntityReferenceFieldItemList

Buggy or inaccurate documentation? Please file an issue. Need support? Need help programming? Connect with the Drupal community.