General help

I want to return response from my web service created in moodle as an object instead of array. So what changes i will need to make in the following function

    public static function get_remote_courses_returns() {
        return new external_multiple_structure(
            new external_single_structure(
                array(                    
                    'response' => new external_value(PARAM_RAW, 'user name'),
                )
            )
        );
    }

Also i dont want to hardcode the response array as shown in the above example. I mean i just want to tell moodle that an object will be returned in the response and the structure of that objected will be decided at the run time.