protected static function export_user_data_notifications(int $userid) {
        global $DB;

        $context = \context_user::instance($userid);

        $notificationdata = [];
        $select = "useridfrom = ? OR useridto = ?";
        $notifications = $DB->get_recordset_select('notifications', $select, [$userid, $userid], 'timecreated ASC');
        foreach ($notifications as $notification) {
            $timeread = !is_null($notification->timeread) ? transform::datetime($notification->timeread) : '-';

            $data = (object) [
                'subject' => $notification->subject,
                'fullmessage' => $notification->fullmessage,
                'smallmessage' => $notification->smallmessage,
                'component' => $notification->component,
                'eventtype' => $notification->eventtype,
                'contexturl' => $notification->contexturl,
                'contexturlname' => $notification->contexturlname,
                'timeread' => $timeread,
                'timecreated' => transform::datetime($notification->timecreated),
                'customdata' => $notification->customdata,
            ];

            $notificationdata[] = $data;
        }
        $notifications->close();

        writer::with_context($context)->export_data([get_string('notifications', 'core_message')], (object) $notificationdata);
    }