@Override
    public void actionPerformed(ActionEvent event) {
      Object source = event.getSource();
      if (source instanceof JTree tree) {
        TreePath path = tree.getLeadSelectionPath();
        if (path != null) {
          if (tree.isExpanded(path) || tree.getModel().isLeaf(path.getLastPathComponent())) {
            int row = tree.getRowForPath(path);
            path = row < 0 ? null : tree.getPathForRow(row + 1);
            if (path != null) {
              tree.setSelectionPath(path);
              tree.scrollPathToVisible(path);
            }
          }
          else {
            tree.expandPath(path);
          }
        }
      }
    }
@Override
    public void actionPerformed(ActionEvent event)