static bool replaceTreeNodeChildren_withDummyChild(final DefaultMutableTreeNode node, fL children, fO dummyChild) {
  if (node == null) false;
  ret swing(func -> bool {
    L oldChildren = mapMethod('getUserObject, node.children());
    if (eq(oldChildren, children)) false;
    node.removeAllChildren();
    for (O c : unnull(children)) {
      DefaultMutableTreeNode node2 = new(c);
      node2.add(new DefaultMutableTreeNode(dummyChild));
      node.add(node2);
    }
    true;
  });
}