Cocos Creator 2.2.1的Websocket服务器功能

我使用:

    if(typeof WebSocketServer == "undefined") {
        console.error("WebSocketServer is not enabled!");
        return;
    }                
    let s = new WebSocketServer();
    s.onconnection = function(conn) {
        conn.ondata = function(data) {
            conn.send(data, (err)=>{});
        }
        conn.onclose = function() { console.log("connection gone!");} ;
    };        
    s.onclose = function() {
      console.log("server is closed!")
    }
    s.listen(8080, (err) => {
       if(!err) console.log("server booted!");
    });

但在iOS和Android环境下,
甚至模拟器中,
都只会出现“WebSocketServer is not enabled!”
真的有把Websocket的服务器功能加入2.2.1中吗?
还是要如何开启功能?

你类名写错了吧 不应该是WebSocket吗