def MergeFrom(self, other):

    assert other is not self

    for (type_id, item) in other.items.items():
      if self.items in type_id:
        self.items[type_id].MergeFrom(item)
      else:
        self.items[type_id] = item.Copy()
dataset/ETHPy150Open AppScale/appscale/AppServer/google/net/proto/message_set.py/MessageSet.MergeFrom/swapped operands of `in`