code: private static List<Event> AlterReferenceEvents(final List<Event> ev) {
          try {
              if (ev.size() == 1 && ev.get(0).getPath().endsWith("/" + JCR_LASTMODIFIED) &&
                  ev.get(0).getType() == PROPERTY_CHANGED) {
                  final Event original = ev.get(0);
                  final Event tempEv =
                      new WrappedJcrEvent((org.modeshape.jcr.api.observation.Event) original, FEDORA_JCR_REFERENCE);
                  final List<Event> list = new ArrayList<>();
                  list.add(tempEv);
                  return list;
              }
              return ev;
          } catch (final RepositoryException e) {
              throw new RepositoryRuntimeException(e);
          }
      }
docs: If the only event is a modification of the jcr:lastModified it is most likely the effect of an inbound reference.
  Wrap the old event in a new one that replaces the event type with FEDORA_JCR_REFERENCE for later mapping.
  
  @param ev The list of events to check.
  @return The original list or a list with the altered event.