@Nullable
  private static PackagingElementNode getNode(Object value) {
    if (!(value instanceof DefaultMutableTreeNode)) return null;
    final Object userObject = ((DefaultMutableTreeNode)value).getUserObject();
    return userObject instanceof PackagingElementNode ? (PackagingElementNode)userObject : null;
  }
@Nullable
  private static PackagingElementNode getNode(Object value)