Callback called whenever the underlying Receiver undergoes a change
        of state. This function can be overridden.

        :param previous_state: The previous Receiver state.
        :type previous_state: ~uamqp.constants.MessageReceiverState
        :param new_state: The new Receiver state.
        :type new_state: ~uamqp.constants.MessageReceiverState

def on_state_changed(self, previous_state, new_state):
        """Callback called whenever the underlying Receiver undergoes a change
        of state. This function can be overridden.

        :param previous_state: The previous Receiver state.
        :type previous_state: ~uamqp.constants.MessageReceiverState
        :param new_state: The new Receiver state.
        :type new_state: ~uamqp.constants.MessageReceiverState
        """
        # pylint: disable=protected-access
        _logger.info("Message receiver %r state changed from %r to %r on connection: %r",
                     self.name, previous_state, new_state, self._session._connection.container_id)
        self._state = new_state