public static function override_activity_completion_status_returns() {

        return new external_single_structure(
            array(
                'cmid' => new external_value(PARAM_INT, 'The course module id'),
                'userid' => new external_value(PARAM_INT, 'The user id to which the completion info belongs'),
                'state'   => new external_value(PARAM_INT, 'The current completion state.'),
                'timecompleted' => new external_value(PARAM_INT, 'time of completion'),
                'overrideby' => new external_value(PARAM_INT, 'The user id who has overriden the status, or null'),
                'tracking'      => new external_value(PARAM_INT, 'type of tracking:
                                                                    0 means none, 1 manual, 2 automatic'),
            )
        );
    }