请教：
使用cocos creator1.7建立一个最简单的测试Websocket项目，但是预览的时候无法启动，见下图及源码，求指教。
脚本源码：
cc.Class({
extends: cc.Component,
properties: {
label: {
default: null,
type: cc.Label
},
// defaults, set visually when attaching this script to the Canvas
text: 'Hello, World!'
},
// use this for initialization
onLoad: function () {
const ws = new WebSocket("ws://localhost:8080/InfoDeptSys/leo");
ws.onopen = function (event) {
console.log("Send Text WS was opened.");
};
ws.onmessage = function (event) {
console.log("response text msg: " + event.data);
this.label.string = event.data;
};
ws.onerror = function (event) {
console.log("Send Text fired an error");
};
ws.onclose = function (event) {
console.log("WebSocket instance closed.");
};
setTimeout(function () {
if (ws.readyState === WebSocket.OPEN) {
ws.send("Hello WebSocket, I'm a text message.");
}
else {
console.log("WebSocket instance wasn't ready...");
}
}, 3);
},
// called every frame
update: function (dt) {
},
});