public static function get_attempt_access_information_returns() {
        return new external_single_structure(
            array(
                'endtime' => new external_value(PARAM_INT, 'When the attempt must be submitted (determined by rules).',
                                                VALUE_OPTIONAL),
                'isfinished' => new external_value(PARAM_BOOL, 'Whether there is no way the user will ever be allowed to attempt.'),
                'ispreflightcheckrequired' => new external_value(PARAM_BOOL, 'whether a check is required before the user
                                                                    starts/continues his attempt.', VALUE_OPTIONAL),
                'preventnewattemptreasons' => new external_multiple_structure(
                                                new external_value(PARAM_TEXT, 'access restriction description'),
                                                                    'list of reasons'),
                'warnings' => new external_warnings(),
            )
        );
    }