static void Main(string[] args)
        {
            TimerManager timer = new TimerManager();
            AlarmClock alarmClock = new AlarmClock(timer);
            Finisher finisher = new Finisher(timer);

            timer.Start(5000);

            alarmClock.Unregister(timer);

            timer.Start(2000);
            Console.ReadKey();
        }