public void SinceHasCorrectResult()
{
DateTime dateTime = new DateTime(1970, 11, 5, 12, 30, 20);
DateTime actual = new TimeSpan(1, 0, 0, 0).Since(dateTime);
Assert.AreEqual(dateTime.AddDays(1).Date, actual.Date);
Assert.AreEqual(dateTime.Second, actual.Second);
Assert.AreEqual(dateTime.Minute, actual.Minute);
Assert.AreEqual(dateTime.Hour, actual.Hour);
}