public override void Remove(Component c) { Console.WriteLine("Can not remove from leaf"); }
public override void Add(Component c) { Console.WriteLine("Can not add to leaf"); }
public override void Remove(Component c) { _childrend.Remove(c); }
public override void Add(Component c) { _childrend.Add(c); }
public abstract void Remove(Component c);
public abstract void Add(Component c);