public void SubscribeInterval()
        {
            using var timeProvider = TestTimeProvider.SetDefault(new DateTime(2020, 03, 15, 17, 0, 0));
            var timerService = new TimerService();

            int intervalsCalled = 0;

            ITimerInterval timerInterval = timerService.SubscribeInterval(TimeSpan.FromHours(1),
                                                                          (ITimerService sender, ITimerInterval interval) =>
            {
                Assert.AreEqual(timerService, sender);
                intervalsCalled++;
                if (intervalsCalled > 1)
                {
                    interval.Unsubscribe();
                }
            });

            timerService.Check();
            Assert.AreEqual(0, intervalsCalled);

            timeProvider.Now += TimeSpan.FromMinutes(31);
            timerService.Check();
            Assert.AreEqual(0, intervalsCalled, "1 hour interval should not have been called after 31 minutes");

            timeProvider.Now += TimeSpan.FromMinutes(31);
            timerService.Check();
            Assert.AreEqual(1, intervalsCalled, "1 hour interval should have been called after 62 minutes");

            timeProvider.Now += TimeSpan.FromMinutes(60);
            timerService.Check();
            Assert.AreEqual(2, intervalsCalled, "should have been called again after 60 minutes");

            timeProvider.Now += TimeSpan.FromMinutes(60);
            timerService.Check();
            Assert.AreEqual(2, intervalsCalled, "should not have been called after unsubscribe");
        }