private CheckedTreeNode insertNewTool(final CheckedTreeNode groupNode, final Tool toolCopy) {
   CheckedTreeNode toolNode = new CheckedTreeNode(toolCopy);
   toolNode.setChecked(toolCopy.isEnabled());
   ((ToolsGroup) groupNode.getUserObject()).addElement(toolCopy);
   groupNode.add(toolNode);
   nodeWasInserted(toolNode);
   return toolNode;
 }
  private CheckedTreeNode insertNewGroup(final ToolsGroup groupCopy) {
    CheckedTreeNode root = getTreeRoot();
    CheckedTreeNode groupNode = new CheckedTreeNode(groupCopy);
    root.add(groupNode);
    for (Tool tool : groupCopy.getElements()) {
      insertNewTool(groupNode, tool);
    }

    return groupNode;
  }