public static void Main(string[] args)
{
MessageSubscriberOne s1 = new MessageSubscriberOne();
MessageSubscriberTwo s2 = new MessageSubscriberTwo();
MessageSubscriberThree s3 = new MessageSubscriberThree();
MessageSubscriberOne s4 = new MessageSubscriberOne();
MessagePublisher p = new MessagePublisher();
p.attach(s1);
p.attach(s2);
p.notifyUpdate(new Message("Initial State"));
p.detach(s1);
p.attach(s3);
p.UpdateState(1);
p.attach(s4);
p.UpdateState(1);
}