@classmethod
  @gen.coroutine
  def _CheckUpdate(cls, client, **ph_dict):
    assert 'photo_id' in ph_dict and 'user_id' in ph_dict, ph_dict
    photo = yield Photo.Query(client, ph_dict['photo_id'], None, must_exist=False)

    if photo is None:
      raise InvalidRequestError('Photo "%s" does not exist and so cannot be updated.' %
                                ph_dict['photo_id'])

    if photo.user_id != ph_dict['user_id']:
      raise PermissionError('User id of photo does not match requesting user')

    raise gen.Return(photo)
Add another node into the peer list.
dataset/ETHPy150Open viewfinderco/viewfinder/backend/db/photo.py/Photo._CheckUpdate--crossover with--dataset/ETHPy150Open saltstack/salt/salt/modules/glusterfs.py/peer