@Override
    public void eventProcessed(ServiceEvent e) {
      ServiceGroupNode group = myGroupRef.get();
      if (group == null || !e.contributorClass.isInstance(group.getRootContributor())) return;

      myGroupRef.set((ServiceGroupNode)findItem(group, myModel.getRoots()));
      notifyListeners(e);
    }
@Override
    public void eventProcessed(ServiceEvent e)