js中 理解 this.initialize.apply ( this, arguments ) 定义对象的方式

var Class = {
create:function() {
return function() {
this.initialize.apply(this, arguments);
};
}
}

var Tool = Class.create();
Tool.prototype = {
initialize: function($container){

this.val = 32;
},
getVal:function(){
return this.val;
},
setVal:function(_val){

this.val = _val;
}
}