public function get_selected_users() {
        global $DB;
        $idlist = array();
        if (!empty($this->filters->userids)) {

            $idlist = explode(',', $this->filters->userids);
            list($where, $params) = $DB->get_in_or_equal($idlist);
            return $DB->get_records_select('user', "id $where", $params);

        }
        return $idlist;
    }