code: private long addStopwatchSplit(Stopwatch stopwatch) {
  		Split split = stopwatch.start();
  		try {
  			randomWait(50, 150);
  		} finally {
  			split.stop();
  		}
  		return split.runningFor() / SimonClock.NANOS_IN_MILLIS;
  	}
docs: Generate a split for a Stopwatch.