public static function bySerializedContentType($contentType)
    {
        switch($contentType)
        {
            case PhpSerializer::SERIALIZED_CONTENT_TYPE:
                $serializer = new PhpSerializer();
                break;
            case JsonSerializer::SERIALIZED_CONTENT_TYPE:
                $serializer = new JsonSerializer();
                break;
            case NullSerializer::SERIALIZED_CONTENT_TYPE:
                $serializer = new NullSerializer();
                break;
            default:
                throw new Exception('Not supported content type!');
        }
        return $serializer;
    }