code: public void add(TracedCallStepAO step){
  		elements.add(step);
  		step.setId((counter++));
  		ReversedCallHelper helper = stepsReversed.get(step.getCall());
  		if (helper == null){
  			helper = new ReversedCallHelper();
  			stepsReversed.put(step.getCall(), helper);
  		}
  		
  		helper.add(step.getNiceId(), step.getTimespent(), step.getDuration());
  		step.setParentId(parentHolder.getParentIdByLayer(step.getLayer(), step.getNiceId()));
  	}
docs: Adds a new TracedCallStepAO.
  @param step