public function col_groups($row) {
        $groups = '';
        if ($usergrps = groups_get_all_groups($this->feedbackstructure->get_cm()->course, $row->userid, 0, 'name')) {
            foreach ($usergrps as $group) {
                $groups .= format_string($group->name). ' ';
            }
        }
        return trim($groups);
    }