code: public void addSplit(long timestampInMs, long durationInNs) {
  		last = durationInNs;
  		total += durationInNs;
  		squareTotal += durationInNs * durationInNs;
  		if (durationInNs > max) {
  			max = durationInNs;
  		}
  		if (durationInNs < min) {
  			min = durationInNs;
  		}
  		counter++;
  		lastTimestamp = timestampInMs;
  	}
docs: Add stopwatch split information.
  
  @param timestampInMs when the split started, expressed in milliseconds
  @param durationInNs how long the split was, expressed in nanoseconds