code: public void addStackedSimons() {
  		Split splitA = SimonManager.getStopwatch("Y.A").start();
  		Split splitB = SimonManager.getStopwatch("Y.B").start();
  		addStopwatchSplits(SimonManager.getStopwatch("Y.C"), 6);
  		splitB.stop();
  		Split splitD = SimonManager.getStopwatch("Y.D").start();
  		randomWait(100, 250);
  		randomWait(100, 250);
  		splitD.stop();
  		splitA.stop();
  	}
docs: Stacked stopwatches to test call tree.