public static function get_subwiki_pages_parameters() {
        return new external_function_parameters (
            array(
                'wikiid' => new external_value(PARAM_INT, 'Wiki instance ID.'),
                'groupid' => new external_value(PARAM_INT, 'Subwiki\'s group ID, -1 means current group. It will be ignored'
                                        . ' if the wiki doesn\'t use groups.', VALUE_DEFAULT, -1),
                'userid' => new external_value(PARAM_INT, 'Subwiki\'s user ID, 0 means current user. It will be ignored'
                                        .' in collaborative wikis.', VALUE_DEFAULT, 0),
                'options' => new external_single_structure(
                            array(
                                    'sortby' => new external_value(PARAM_ALPHA,
                                            'Field to sort by (id, title, ...).', VALUE_DEFAULT, 'title'),
                                    'sortdirection' => new external_value(PARAM_ALPHA,
                                            'Sort direction: ASC or DESC.', VALUE_DEFAULT, 'ASC'),
                                    'includecontent' => new external_value(PARAM_INT,
                                            'Include each page contents or just the contents size.', VALUE_DEFAULT, 1),
                            ), 'Options', VALUE_DEFAULT, array()),
            )
        );
    }