static void Main(string[] args)
        {
            Observable
                .Timer(TimeSpan.FromSeconds(0.5), Scheduler.Immediate)
                .Do(_ => Debug.WriteLine("Start"))
                .SelectMany(_ => Observable.Timer(TimeSpan.FromSeconds(1))) // timer simulates FromAsyncPattern call
                .Do(_ => Debug.WriteLine("Finish"))
                .Repeat()
                .Subscribe();

            Console.ReadLine();
        }