name: Function.bindAsEventListener
This provides a new method to the core class Function. The method,called bindAsEventListener(),is used to do bind methods to event handlers.
这为核心class 函数支持了一个新的方法。这个方法叫bindAsEventListener(),是用来绑定方法给事件处理器的。
var obj = new SomeClass();
var closure = obj.someMethod.bindAsEventListener(this);
element.onclick = closure;