func TestUpgradeResponse(t *testing.T) {
	testCases := []struct {
		connectionHeader string
		upgradeHeader    string
		shouldError      bool
	}{
		{
			connectionHeader: "",
			upgradeHeader:    "",
			shouldError:      true,
		},
		{
			connectionHeader: "Upgrade",
			upgradeHeader:    "",
			shouldError:      true,
		},
		{
			connectionHeader: "",
			upgradeHeader:    "SPDY/3.1",
			shouldError:      true,

	connectionHeader := strings.ToLower(req.Header.Get(httpstream.HeaderConnection))
	upgradeHeader := strings.ToLower(req.Header.Get(httpstream.HeaderUpgrade))
	if !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {

	"k8s.io/apimachinery/pkg/util/httpstream"
	utilnettesting "k8s.io/apimachinery/pkg/util/net/testing"
)

type serverHandlerConfig struct {
	shouldError      bool
	statusCode       int
	connectionHeader string
	upgradeHeader    string
}

func serverHandler(t *testing.T, config serverHandlerConfig) http.HandlerFunc {
	return func(w http.ResponseWriter, req *http.Request) {
		if config.shouldError {

func (s *SpdyRoundTripper) NewConnection(resp *http.Response) (httpstream.Connection, error) {
	connectionHeader := strings.ToLower(resp.Header.Get(httpstream.HeaderConnection))
	upgradeHeader := strings.ToLower(resp.Header.Get(httpstream.HeaderUpgrade))
	if (resp.StatusCode != http.StatusSwitchingProtocols) || !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {

	if u.err != nil {
		return u.err
	}

	if backendResponse.StatusCode == http.StatusSwitchingProtocols {
		connectionHeader := strings.ToLower(backendResponse.Header.Get(httpstream.HeaderConnection))
		upgradeHeader := strings.ToLower(backendResponse.Header.Get(httpstream.HeaderUpgrade))
		if !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(spdy.HeaderSpdy31)) {

			"Host: test\r\n" +
			tt.connectionHeader() +
			"Transfer-Encoding: chunked\r\n" +
			"\r\n")
		cw := internal.NewChunkedWriter(&conn.readBuf)
		io.WriteString(cw, body)
		cw.Close()
		conn.readBuf.WriteString("\r\n")
	} else {
		conn.readBuf.Write([]byte(fmt.Sprintf(
			"POST / HTTP/1.1\r\n"+
				"Host: test\r\n"+
				tt.connectionHeader()+
				"Content-Length: %d\r\n"+