static public void Run() { Console.WriteLine("------------Memento------------"); ComputerSystem computerSystem = new ComputerSystem("4.12"); SystemHistory history = new SystemHistory(); history.Points.Push(computerSystem.CreateSystemPoint()); computerSystem.Version = "5.01"; Console.WriteLine("New Version: " + computerSystem.Version); computerSystem.RestoreSystem(history.Points.Pop()); Console.WriteLine("Version after restore: " + computerSystem.Version); }