public static void main(String[] args) {
Subject subject = new MySubject();
Observer observer1 = new MyObserver(1);
Observer observer2 = new MyObserver(2);
Observer observer3 = new MyObserver(3);
subject.attach(observer1);
subject.attach(observer2);
subject.attach(observer3);
subject.notice();
subject.detach(observer1);
subject.notice();
}
