public void Unregister(AbstractObserver observer) { if (this.observers.Contains(observer)) { observers.Remove(observer); } }
public void Register(AbstractObserver observer) { if (!this.observers.Contains(observer)) { observers.Add(observer); } }
public void Unregister(AbstractObserver observer) { observers.Remove(observer); }
public void Register(AbstractObserver observer) { observers.Add(observer); }