code: public void onRootStopwatchStop(CallTree callTree, Split split) {
  		callTreeLogTemplate.log(split, callTree);
  		if (logThreshold != null && split.runningFor() > logThreshold) {
  			split.getStopwatch().setAttribute(ATTR_NAME_LAST, callTree);
  		}
  		removeCallTree();
  	}
docs: When stopwatch corresponding to root tree node is stopped, this method is called.
  Logs call tree when split is longer than threshold.
  
  @param callTree call tree to log
  @param split stopped split