How to use the faye-websocket function in faye-websocket

this.app.on('upgrade', (request, socket, body) => {
      if (!WebSocket.isWebSocket(request)) return;
      var ws = new WebSocket(request, socket, body);

      ws.on('message', event => {
        var data = event.data, json;
        try {
          json = JSON.parse(event.data);
          if (typeof json.command === 'string') {
            this.handleCommand(json);
          }
        } catch(e) { }
      });

      ws.on('close', event => {
        this.sockets = this.sockets.filter( sock => (sock !== ws) );
        ws = null;
      });

constructor (req, socket, head, options = {}) {
    super();
    this.options = options;
    this.ws = new WebSocket(req, socket, head);
    this.ws.onmessage = this.message.bind(this);
    this.ws.onclose = this.close.bind(this);
    this.id = this.uniqueId('ws');
  }