mosca给出了这个错误：

TypeError: Client is not a constructor
    at new KafkaAscoltatore (/home/x/Desktop/broker/node_modules/mosca/node_modules/ascoltatori/lib/kafka_ascoltatore.js:59:26)
    at Object.build (/home/x/Desktop/broker/node_modules/mosca/node_modules/ascoltatori/lib/ascoltatori.js:77:12)
    at /home/x/Desktop/broker/node_modules/mosca/lib/server.js:181:40
    at makeCall (/home/x/Desktop/broker/node_modules/fastseries/series.js:117:7)
    at ResultsHolder.release (/home/x/Desktop/broker/node_modules/fastseries/series.js:96:9)
    at series (/home/x/Desktop/broker/node_modules/fastseries/series.js:39:14)
    at Object.series (/home/x/Desktop/broker/node_modules/steed/steed.js:90:7)
    at new Server (/home/x/Desktop/broker/node_modules/mosca/lib/server.js:171:9)
    at Object.<anonymous> (/home/x/Desktop/broker/broker.js:118:14)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:266:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:596:3)

环境

节点version:v10.9.0
Kafka结version:latest
莫斯卡version:latest

我试过的

我打开了 /home/x/Desktop/broker/node_modules/mosca/node_modules/ascoltatori/lib/kafka_ascoltatore.js 而看了下面这行后发现问题与Kafka节点版本有关：

this._opts.kafka = this._opts.kafka || require("kafka-node");

当我离开的时候 this._opts.kafka ，开始运作良好。然后我打印了这两个版本，我发现新版本中没有客户端构造函数。这是我的打印结果： this._opts.kafka (kafka-node v4.0.1 latest) 返回没有客户端的highlevelproducer，另一方面require（“kafka节点”）（v0.5.9）返回highlevelconsumer。

代码：

var backend = {
    type: "kafka",
    kafka: require('kafka-node'),
    json: false,
    connectionString: "IP:2181",
    defaultEncoding: "utf8",
};

var moscaSettings = {
    interfaces: [
        { type: "mqtt", port: PORT }
    ],
    id: "mosca",
    stats: false,
    publishNewClient: false,
    publishClientDisconnect: false,
    publishSubscriptions: false,
    backend: backend,
};
var server = new mosca.Server(moscaSettings); // Error pops here

我可以让Kafka和我上面提到的旧版本一起工作，但我认为这只是一个快速的解决方案，所以我希望有人能给我一个合适的解决方案。