code: protected void registerEventHelpers ()
      {
          try {
              _helpers.put(ObjectDestroyedEvent.class, new EventHelper () {
                  public boolean invoke (DEvent event, DObject target) {
                      return objectDestroyed(event, target);
                  }
              });
              _helpers.put(ObjectAddedEvent.class, new EventHelper() {
                  public boolean invoke (DEvent event, DObject target) {
                      return objectAdded(event, target);
                  }
              });
              _helpers.put(ObjectRemovedEvent.class, new EventHelper() {
                  public boolean invoke (DEvent event, DObject target) {
                      return objectRemoved(event, target);
                  }
              });
  
          } catch (Exception e) {
              log.warning("Unable to register event helpers", "error", e);
          }
      }
docs: Registers our event helper methods.