var Common={
    data:100,
    conf:{},
    init:function(param){
        this.conf=param;
   },
    say:function(){
        console.log('say : '+ this.data+this.conf);
    }
};

 function Some(param){
     this.init(param);
 }
Some.prototype=Common;
 function Factory(param){
   return new Some(param);  
 }

var a =Factory({a:100,b:200});
  a.say();
  console.log("\n--------");
  console.log(a.config);
  

想实现的是缺省值由Common提供 ,在Factory每次new的时候能够动态传入参数,但是 a.say执行有结果,但是打印 a.conf却是空