public static function get_subwiki_pages_returns() {

        return new external_single_structure(
            array(
                'pages' => new external_multiple_structure(
                    new external_single_structure(
                        array(
                            'id' => new external_value(PARAM_INT, 'Page ID.'),
                            'subwikiid' => new external_value(PARAM_INT, 'Page\'s subwiki ID.'),
                            'title' => new external_value(PARAM_RAW, 'Page title.'),
                            'timecreated' => new external_value(PARAM_INT, 'Time of creation.'),
                            'timemodified' => new external_value(PARAM_INT, 'Time of last modification.'),
                            'timerendered' => new external_value(PARAM_INT, 'Time of last renderization.'),
                            'userid' => new external_value(PARAM_INT, 'ID of the user that last modified the page.'),
                            'pageviews' => new external_value(PARAM_INT, 'Number of times the page has been viewed.'),
                            'readonly' => new external_value(PARAM_INT, '1 if readonly, 0 otherwise.'),
                            'caneditpage' => new external_value(PARAM_BOOL, 'True if user can edit the page.'),
                            'firstpage' => new external_value(PARAM_BOOL, 'True if it\'s the first page.'),
                            'cachedcontent' => new external_value(PARAM_RAW, 'Page contents.', VALUE_OPTIONAL),
                            'contentformat' => new external_format_value('cachedcontent', VALUE_OPTIONAL),
                            'contentsize' => new external_value(PARAM_INT, 'Size of page contents in bytes (doesn\'t include'.
                                                                            ' size of attached files).', VALUE_OPTIONAL),
                            'tags' => new external_multiple_structure(
                                \core_tag\external\tag_item_exporter::get_read_structure(), 'Tags', VALUE_OPTIONAL
                            ),
                        ), 'Pages'
                    )
                ),
                'warnings' => new external_warnings(),
            )
        );
    }