text: /**
   * @name: Function.prototype.bind
   * @description: 创建一个新的函数, 当被调用时，将其this关键字设置为提供的值，在调用新函数时，在任何提供之前提供一个给定的参数序列。
   * @author: lizijie
   * @update: 2017-05-31
   */
  
  Function.prototype.bind = function(thisArg) {
  	let arr = [];
  	let _this = this;
  	for (let i = 1, len = arguments.length; i < len; i++) {
  		arr.push(arguments[i]);
  	}
  	let F = function() {};
  	F.prototype = this.prototype;
  	let bound = function() {
  		let innerArgs = Array.prototype.slice.call(arguments);
  		let finalArgs = arr.concat(innerArgs);
  		// let context = thisArg || window;
  		// context.fn = _this;
  		// let result = eval("context.fn(" + finnalArgs + ")");
  		// delete context.fn;
  		// return result;
  		return _this.apply(this instanceof F ? this : thisArg || this, finalArgs);
  	}
  	bound.prototype = new F();
  	return bound;
  }