@Override
      public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_SPACE) {
          TreePath treePath = tree.getLeadSelectionPath();
          DefaultMutableTreeNode node = (DefaultMutableTreeNode)treePath.getLastPathComponent();
          toggleNode(tree, node);
          e.consume();
        }
      }
@Override
      public void keyPressed(KeyEvent e)