Given a message, route it either to the incoming queue, or to the
        future associated with its correlation_id.

async def route_msg(self, msg):
        """Given a message, route it either to the incoming queue, or to the
        future associated with its correlation_id.
        """
        if msg.correlation_id in self._futures:
            self._set_reply(msg.correlation_id, msg)
        else:
            await self._push_incoming(msg)