15-1 overriding wrap

package overriding15;
 
class Box
{
    public void simpleWrap(){System.out.println("simple wrap");}
    public void Wrap(){ simpleWrap();}
}
 
class PaperBox extends Box
{
    public void paperWrap() {System.out.println("paper wrap");}
    public void Wrap(){ paperWrap();}
}
 
class GoldPaperBox extends PaperBox
{
    public void goldWrap() {System.out.println("gold wrap");}
    public void Wrap(){ goldWrap();}
}
///////////////////////
class InstanceOf
{
    public static void wrapBox(Box box)
    {
        box.Wrap();
    }
    
    public static void main(String[] args)
    {
        Box box1=new Box();
        PaperBox box2=new PaperBox();
        GoldPaperBox box3=new GoldPaperBox();
        // 여기까지 그냥 가리키는거,  생성자 딱히 없음.
        wrapBox(box1);
        wrapBox(box2);
        wrapBox(box3);
    }
}