@Override
  public void readExternal(Element element) throws InvalidDataException {
    super.readExternal(element);
    for (Element elem : element.getChildren(NodeRendererSettings.RENDERER_TAG)) {
      String role = elem.getAttributeValue("role");
      if (role == null) {
        continue;
      }
      if ("label".equals(role)) {
        myLabelRenderer = (ValueLabelRenderer)myRendererSettings.readRenderer(elem);
      }
      else if ("children".equals(role)) {
        myChildrenRenderer = (ChildrenRenderer)myRendererSettings.readRenderer(elem);
      }
    }
  }
@Override
  public void readExternal(Element element)