如何从javascript中的另一个类回调读取修改后的类属性?

我有两门关于websockets的课。它们应该用于通过程序作为中介将信息从一个发送到另一个。WSS会监听,并且只能有一个连接。我与另一台服务器建立了客户端连接。在我的主函数中,我实例化了这些对象中的每一个,并将forwardMessage(event)作为回调(onmessage)分配给监听器。它本质上应该转发内容,但问题是,即使在客户端连接到serverWSS对象后,回调也总是将activeWS报告为null。我不确定如何通过这种方式在两者之间找到参考。

class WSS {
    constructor(){
        const WebSocket = require('ws');
        this.wss = new WebSocket.Server({ port: 3001});
        this.activeWs = null;

        this.wss.on('connection', function connection(ws) {
            console.log("Client Connected");
            if (this.activeWs != null) {
                this.activeWs.close(1000, "Server initiated close");
                console.log("Closed old session")
            }
            this.activeWs = ws;
        })

        this.sendCommand = (data) => {
            console.log(this.activeWs)
            if (this.activeWs == null) {
                return;
            }
            console.log(data);
        }
    }
}

class WS {
    constructor(clientId, onmessage) {
        this.clientId = clientId;
        const WebSocket = require('ws');
        this.ws = new WebSocket('localhost:8080');
        this.ws.onmessage = (event) => { onmessage(event)};
    }
}

serverWSS = new WSS();
listener = new WS("000", forwardMessage)

function forwardMessage(event) {
    serverWSS.sendCommand(event.data);
}