if err != nil {
			return nil, nil, err
		}
	} else {
		upgrader, err = spdyStream.NewRoundTripper(tlsConfig)
		if err != nil {
			return nil, nil, err
		}
	}
	wrapper, err := rest.HTTPWrappersForConfig(restConfig, upgrader)
	if err != nil {
		return nil, nil, fmt.Errorf("failed creating SPDY upgrade wrapper: %w", err)
	}
	return wrapper, upgrader, nil