public static void main(String[] args) {
        Director director=new Director();
        Builder b1=new ConcreteBuilder1();
        Builder b2=new ConcreteBuilder2();
        director.construct(b1);
        Product d1=b1.getResult();
        d1.show();
        director.construct(b2);
        Product d2=b2.getResult();
        d2.show();
	}