Doctrine\Tests\ORM\Mapping\AbstractContentItem:
  type: mappedSuperclass
  id:
    id: 
      type: integer
      unsigned: true
      generator:
        strategy: AUTO
  fields:
    # FilesystemIdentifier
  manyToOne:
    parentDirectory:
      targetEntity: Doctrine\Tests\ORM\Mapping\Directory
      joinColumn:
        name: parent_directory_id
        referencedColumnName: id