public void Until()
 {
     var now = DateTime.UtcNow;
     var s = new Sleep();
     s.Until(DateTime.UtcNow.AddMilliseconds(251));
     Assert.IsTrue(now.AddMilliseconds(250) < DateTime.UtcNow);
 }
 public void UntilPast()
 {
     var s = new Sleep();
     s.Until(DateTime.UtcNow.AddMilliseconds(-251));
 }