Hello, I tried to this in the beginning :
public static void haveFun(Person person) {
        if(person instanceof Player)
        {
            person.play();
        }
        else if(person instanceof Dancer)
        {
            person.dance();
        }
But it didn't work. Then, I tried this :
public static void haveFun(Person person) {
        if(person instanceof Player)
        {
            Player.play();
        }
        else if(person instanceof Dancer)
        {
            Dancer.dance();
        }
And it is still not working. Why ?