public void ManualTestClock_GetMillisecondTimestamp_DoesntAdvanceAutomatically()
        {
            var clock = new ManualTestClock();

            Thread.Sleep(10);
            Assert.Equal(0, clock.GetMillisecondTimestamp());
        }
        public void ManualTestClock_GetMillisecondTimestamp_UpdatesAfterAddingMillis()
        {
            var clock = new ManualTestClock();

            clock.AddMilliseconds(20);
            Assert.Equal(20, clock.GetMillisecondTimestamp());
        }
        public void ManualTestClock_GetMillisecondTimestamp_StartsAtZero()
        {
            var clock = new ManualTestClock();

            Assert.Equal(0, clock.GetMillisecondTimestamp());
        }