for (Object o : getNodes())
    {
      Node node = (Node) o;
      Interaction inter = null;
      if (node instanceof ChbConversion)
      {
        inter = ((ChbConversion) node).getConversion();
      }
      else if (node instanceof ChbControl)
      {
        inter = ((ChbControl) node).getControl();
      }
      else if (node instanceof Hub)
      {
        inter = ((Hub) node).getInteraction();
      }
      if (inter != null)
      {
        if (!interactionMap.containsKey(inter))
        {
          interactionMap.put(inter, new ArrayList<GraphObject>());
        }
        interactionMap.get(inter).add(node);
      }
    }
    for (Object o : getEdges())
    {
      Interaction inter = null;
      if (o instanceof NonModulatedEffector)
      {
        inter = ((NonModulatedEffector) o).getControl();
      }