public void ShouldDoNothingForSetAmountOfTime() { // Given const double accuracyOfTimeMeasurementInMilliseconds = 25d; const double millisecondsToSleep = 500d; var stopwatch = new Stopwatch(); stopwatch.Reset(); var template = new SleeperTemplate { SleepTimeInMilliseconds = (int)millisecondsToSleep }; var sleeper = new Sleeper(template); // When stopwatch.Start(); sleeper.ProcessImage(null); stopwatch.Stop(); // Then Assert.AreEqual(millisecondsToSleep, stopwatch.ElapsedMilliseconds, accuracyOfTimeMeasurementInMilliseconds); }