t.DialContext = defaultTransport.DialContext
	}
	if t.TLSHandshakeTimeout == 0 {
		t.TLSHandshakeTimeout = defaultTransport.TLSHandshakeTimeout
	}
	if t.IdleConnTimeout == 0 {
		t.IdleConnTimeout = defaultTransport.IdleConnTimeout
	}
	return t
}

// SetTransportDefaults applies the defaults from http.DefaultTransport
// for the Proxy, Dial, and TLSHandshakeTimeout fields if unset

	if !EnableHTTP2Probing {
		return t, nil
	}
	if t.TLSHandshakeTimeout == 0 {
		t.TLSHandshakeTimeout = defaultTransport.TLSHandshakeTimeout
	}
	if t.IdleConnTimeout == 0 {
		t.IdleConnTimeout = defaultTransport.IdleConnTimeout
	}
	t2, err := http2.ConfigureTransports(t)
	if err != nil {
		return nil, err
	}
	t2.ReadIdleTimeout = time.Duration(30) * time.Second

		httpClient.Transport = &http.Transport{
			Proxy:           http.ProxyFromEnvironment,
			TLSClientConfig: config,
			DialContext: (&net.Dialer{
				Timeout: time.Second * 10,
			}).DialContext,
			IdleConnTimeout:       90 * time.Second,
			TLSHandshakeTimeout:   10 * time.Second,
			ExpectContinueTimeout: 1 * time.Second,
		}

		retryBackoffTime := firstRetryBackOffTime
		startTime := time.Now()

	var updateTransport http.RoundTripper = &http.Transport{
		Proxy:                 http.ProxyFromEnvironment,
		DialContext:           xhttp.NewInternodeDialContext(timeout, globalTCPOptions),
		IdleConnTimeout:       timeout,
		TLSHandshakeTimeout:   timeout,
		ExpectContinueTimeout: timeout,
		TLSClientConfig: &tls.Config{
			RootCAs:            globalRootCAs,

			Proxy: http.ProxyFromEnvironment,
			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
				return &fakeConn{err: expectedErr}, nil
			},
			MaxIdleConns:          100,
			IdleConnTimeout:       90 * time.Second,
			TLSHandshakeTimeout:   10 * time.Second,
			ExpectContinueTimeout: 1 * time.Second,
		}
		responder = &fakeResponder{t: t, w: w}
		proxyHandler := NewUpgradeAwareHandler(
			&url.URL{