@Nullable
  public InspectionConfigTreeNode.Group getStrictlySelectedGroupNode() {
    TreePath[] paths = getTree().getSelectionPaths();
    return paths != null && paths.length == 1 && paths[0].getLastPathComponent() instanceof InspectionConfigTreeNode.Group
           ? (InspectionConfigTreeNode.Group)paths[0].getLastPathComponent()
           : null;
  }
@Nullable
  public InspectionConfigTreeNode.Group getStrictlySelectedGroupNode()