怎样用Javascript实现建造者模式

function Fangzi(){
    this.woshi = "";
    this.keting = "";
    this.chufang = "";
}

function Baogongtou(){
    this.jianfangzi = function(gongren){
        gongren.jian_woshi();
        gongren.jian_keting();
        gongren.jian_chufang();
    }
}

function Gongren(){
    this.jian_woshi = function(){
        console.log("卧室建好了!");
    }

    this.jian_keting = function(){
        console.log("客厅建好了！");
    }

    this.jian_chufang = function(){
        console.log("厨房建好了！");
    }

    this.wangong = function(){
        var fangzi = new Fangzi();
        fangzi.woshi = "ok";
        fangzi.keting = "ok";
        fangzi.chufang = "ok";
        return fangzi;
    }
}
let gongren = new Gongren();
let baogongtou = new Baogongtou();
//卧室建好了!
//客厅建好了！
//厨房建好了！
baogongtou.jianfangzi(gongren);
var my_fangzi = gongren.wangong();
/*
Fangzi={
       chufang: "ok"
       keting: "ok"
       woshi: "ok"
       }
*/
console.log(my_fangzi);