code: protected Deque<XMLEvent> getAdditionalEvents(XMLEvent event) {
          final XMLEvent additionalEvent = this.getAdditionalEvent(event);
          if (additionalEvent == null) {
              return null;
          }
  
          final Deque<XMLEvent> additionalEvents = new LinkedList<XMLEvent>();
          additionalEvents.push(additionalEvent);
          return additionalEvents;
      }
docs: The Deque with the additional events WILL BE MODIFIED by the calling code.
  
  @param event The current event
  @return Any additional events that should be injected before the current event. If null the
  current event is returned