cocos2d-x jsb报错cc.Menu.extend is not a function在jsb下继承不了，加了cc.Menu.extend = cc.Class.extend也没继承不来

cocos2d-x JavaScript
#1

cocos2d-x jsb报错cc.Menu.extend is not a function在jsb下继承不了，加了cc.Menu.extend = cc.Class.extend也没继承不来，在浏览器里可以继承，请问有解决方法么？

#2

Please uses English in the forum.
Do you mean that cc.Menu.extend was not defined?