private static void Main(string[] args)
{
// canonical example
var subject = new ConcreteSubject();
var observer1 = new ConcreteObserver(1);
var observer2 = new ConcreteObserver(2);
subject.Attach(observer1);
subject.Attach(observer2);
subject.SetState(new List <string>());
subject.UpdateStatePartially("yoyo");
subject.UpdateStatePartially("ahahha");
}
