def subscribe_multi(self, topics):
        """Subscribe to some topics."""
        if self.sock == NC.INVALID_SOCKET:
            return NC.ERR_NO_CONN
        
        self.logger.info("SUBSCRIBE: %s", ', '.join([t for (t,q) in topics]))
        return self.send_subscribe(False, [(utf8encode(topic), qos) for (topic, qos) in topics])