@Override
    public DNamedElement valueOf(DefaultMutableTreeNode treeNode) {
      Object userObject = treeNode.getUserObject();
      if (userObject instanceof DClassElement) return ((DClassElement)userObject);
      if (userObject instanceof DPropertyElement) return ((DPropertyElement)userObject);
      if (userObject instanceof DMethodElement) return ((DMethodElement)userObject);

      return null;
    }
@Override
    public DNamedElement valueOf(DefaultMutableTreeNode treeNode)