code: def line_print(self):
          
          inv_types = {v: k for k, v in defines.Types.items()}
  
          if self._code is None:
              self._code = defines.Codes.EMPTY.number
  
          msg = "From {source}, To {destination}, {type}-{mid}, {code}-{token}, ["\
              .format(source=self._source, destination=self._destination, type=inv_types[self._type], mid=self._mid,
                      code=defines.Codes.LIST[self._code].name, token=self._token)
          for opt in self._options:
              msg += "{name}: {value}, ".format(name=opt.name, value=opt.value)
          msg += "]"
          if self.payload is not None:
              if isinstance(self.payload, dict):
                  tmp = list(self.payload.values())[0][0:20]
              else:
                  tmp = self.payload[0:20]
              msg += " {payload}...{length} bytes".format(payload=tmp, length=len(self.payload))
          else:
              msg += " No payload"
          return msg
docs: Return the message as a one-line string.
  
          :return: the string representing the message