code: public function entity(array $data = [])
      {
          $member = new Member();
          $member->role = $data['role'];
          unset($data['role']);
  
          // @todo ここでFactoryオブジェクトを生成するのをなんとかしたい...
          $userFactory = new UserFactory();
          $member->account = $userFactory->entity($data);
  
          return $member;
      }
docs: @param array $data
  
  @return Member