重写es5 中的 bind

	 Function.prototype.myBind = function(){var argu = arguments,_self = this;return function(){var params = [];for(var i = 1 ,len = argu.length ; i < len ; i++){params.push(argu[i]);}params = params.concat(Array.prototype.slice.call(arguments));return _self.apply(argu[0],params);}}

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