code: def subscribe_multi(self, 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])
docs: Subscribe to some topics.