public static function getDocumentClassName($shortName, $gatewayClass)
    {
        $shortName = ucfirst($shortName);
        
        // replace underscores with namespace marker, PSR-0 style
        $shortName = str_replace('_', '\\', $shortName);

        $class = self::getGatewayNamespace($gatewayClass);
        $class .= '\\Document\\'.$shortName;
        if (!class_exists($class)) {
            $class = '\\Argentum\\Common\\Document\\'.$shortName;
        }

        return $class;
    }