自己实现一个bind函数

Function.prototype.myBind = function (){
    if(typeof this !== 'function') throw new TypeError('@');
    var fn_self = this,
        fn_args = Array.prototype.slice.call(arguments,1);
    var fn_empty = function (){}
    var fn = function (){
        return fn_self.apply(this instanceof fn ? this : arguments[0],fn_args.concat(Array.prototype.slice.call(arguments)))
    }
    if(this.prototype){
        fn_empty.prototype = this.prototype;
    }
    fn.prototype = new fn_empty();
    return fn;
}