def _on_receive(self, msg):
        """
        Callback registered for the handle with :class:`Router`; appends data
        to the internal queue.
        """
        _vv and IOLOG.debug('%r._on_receive(%r)', self, msg)
        self._latch.put(msg)
        if self.notify:
            self.notify(self)
Callback registered for the handle with :class:`Router`; appends data
        to the internal queue.