public static function get_user_timers_returns() {
        return new external_single_structure(
            array(
                'timers' => new external_multiple_structure(
                    new external_single_structure(
                        array(
                            'id' => new external_value(PARAM_INT, 'The attempt id'),
                            'lessonid' => new external_value(PARAM_INT, 'The lesson id'),
                            'userid' => new external_value(PARAM_INT, 'The user id'),
                            'starttime' => new external_value(PARAM_INT, 'First access time for a new timer session'),
                            'lessontime' => new external_value(PARAM_INT, 'Last access time to the lesson during the timer session'),
                            'completed' => new external_value(PARAM_INT, 'If the lesson for this timer was completed'),
                            'timemodifiedoffline' => new external_value(PARAM_INT, 'Last modified time via webservices.'),
                        ),
                        'The timers'
                    )
                ),
                'warnings' => new external_warnings(),
            )
        );
    }