How to use the moleculer.Transporters.MQTT function in moleculer

gateway = new GraphQLGateway({
      broker,
      onServiceDiscovery,
    });

    authorBroker = new ServiceBroker({
      nodeID: 'author',
      namespace: 'serviceDiscovery',
      transporter: new Transporters.MQTT('mqtt://localhost:1883'),
    });

    bookBroker = new ServiceBroker({
      nodeID: 'book',
      namespace: 'serviceDiscovery',
      transporter: new Transporters.MQTT('mqtt://localhost:1883'),
    });

    chapterBroker = new ServiceBroker({
      nodeID: 'chapter',
      namespace: 'serviceDiscovery',
      transporter: new Transporters.MQTT('mqtt://localhost:1883'),
    });

    authorBroker.createService(authorSvc);
    bookBroker.createService(bookSvc);
    chapterBroker.createService(chapterSvc);
  });

transporter: new Transporters.MQTT('mqtt://localhost:1883')
      });

      authorBroker = new ServiceBroker({
        nodeID: 'author',
        transporter: new Transporters.MQTT('mqtt://localhost:1883')
      });

      bookBroker = new ServiceBroker({
        nodeID: 'book',
        transporter: new Transporters.MQTT('mqtt://localhost:1883')
      });

      chapterBroker = new ServiceBroker({
        nodeID: 'chapter',
        transporter: new Transporters.MQTT('mqtt://localhost:1883')
      });

      broker.start();

      gateway = new GraphQLGateway({
        broker,
      });

      gateway.start().then(() => done());

      authorBroker.createService(authorSvc);
      bookBroker.createService(bookSvc);
      chapterBroker.createService(chapterSvc);

      authorBroker.start();
      bookBroker.start();