public function getRecord($id)
    {
        $className = $this->config()->get('tree_class');
        if (!$className) {
            return null;
        }
        if ($id instanceof $className) {
            return $id;
        }
        if ($id === 'root') {
            return DataObject::singleton($className);
        }
        if (is_numeric($id)) {
            return DataObject::get_by_id($className, $id);
        }
        return null;
    }