def user_id()

in uamqp/message.py [0:0]


    def user_id(self, value):
        if isinstance(value, str):
            value = value.encode(self._encoding)
        elif value is not None and not isinstance(value, bytes):
            raise TypeError("user_id must be bytes or str.")
        # user_id is type of binary according to the spec.
        # convert byte string into bytearray then wrap the data into c_uamqp.BinaryValue.
        if value is not None:
            self._user_id = utils.data_factory(
                bytearray(value), encoding=self._encoding
            )
        else:
            self._user_id = None