code: async def message(self, msg, msg_type=None, use_version=None):
          
          elem_type = msg_type if msg_type is not None else msg.__class__
          msg = elem_type() if msg is None else msg
          if hasattr(elem_type, "serialize_archive"):
              version = await self.version(elem_type, None, elem=msg) if use_version is None else use_version
              return await msg.serialize_archive(self, version=version)
  
          mtype = msg.__class__ if msg_type is None else msg_type
          fields = mtype.f_specs()
          if hasattr(mtype, "serialize_archive"):
              raise ValueError("Cannot directly load, has to use archive with %s" % mtype)
  
          await self.message_fields(msg, fields)
          return msg
docs: Loads/dumps message
          :param msg:
          :param msg_type:
          :param use_version:
          :return: