cocos2d-js 如何创建单例类

Cocos2d-x JavaScript
#1

cocos2d-js 怎么创建单例类？ 能给给例子吗？

#2 
testClass = cc.Class.extend({
});
testClass._instance = null;
testClass.getInstance = function(){
if(testClass._instance == null){
testClass._instance = new testClass();
}
return testClass._instance;
};


```