public static function get_page_data_parameters() {
        return new external_function_parameters (
            array(
                'lessonid' => new external_value(PARAM_INT, 'lesson instance id'),
                'pageid' => new external_value(PARAM_INT, 'the page id'),
                'password' => new external_value(PARAM_RAW, 'optional password (the lesson may be protected)', VALUE_DEFAULT, ''),
                'review' => new external_value(PARAM_BOOL, 'if we want to review just after finishing (1 hour margin)',
                    VALUE_DEFAULT, false),
                'returncontents' => new external_value(PARAM_BOOL, 'if we must return the complete page contents once rendered',
                    VALUE_DEFAULT, false),
            )
        );
    }