* to a remote host. Newer TLS options are quite useful:
 *
 *  * Server Name Indication (SNI) enables one IP address to negotiate secure connections for
 *    multiple domain names.
 *
 *  * Application Layer Protocol Negotiation (ALPN) enables the HTTPS port (443) to be used to
 *    negotiate HTTP/2.
 *
 * Unfortunately, older HTTPS servers refuse to connect when such options are presented. Rather than

// RoundTripper. The primary use of this method is to support proxying upgradable connections.
// For this reason this method will prefer to negotiate http/1.1 if the URL scheme is https.
// If you wish to ensure ALPN negotiates http2 then set NextProto=[]string{"http2"} in the
// TLSConfig of the http.Transport
func DialURL(ctx context.Context, url *url.URL, transport http.RoundTripper) (net.Conn, error) {

        "TLS-ECH-Client-Reject-NoClientCertificate-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-Reject-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-TLS12-RejectRetryConfigs": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-Rejected-OverrideName-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",

		}

		for _, p := range test.clientProtocols {
			req.Header.Add(HeaderProtocolVersion, p)
		}

		w := newResponseWriter()
		negotiated, err := Handshake(req, w, test.serverProtocols)

		// verify negotiated protocol
		if e, a := test.expectedProtocol, negotiated; e != a {
			t.Errorf("%s: protocol: expected %q, got %q", name, e, a)
		}

		if test.expectError {
			if err == nil {

  internal const val B0_FLAG_FIN = 128

  /** Byte 0 reserved flag 1. Must be 0 unless negotiated otherwise. */
  internal const val B0_FLAG_RSV1 = 64

  /** Byte 0 reserved flag 2. Must be 0 unless negotiated otherwise. */
  internal const val B0_FLAG_RSV2 = 32

  /** Byte 0 reserved flag 3. Must be 0 unless negotiated otherwise. */
  internal const val B0_FLAG_RSV3 = 16

  /** Byte 0 mask for the frame opcode. */

  ) {
  }

  /** Called after the TLS handshake to release resources allocated by [configureTlsExtensions]. */
  open fun afterHandshake(sslSocket: SSLSocket) {
  }

  /** Returns the negotiated protocol, or null if no protocol was negotiated. */
  open fun getSelectedProtocol(sslSocket: SSLSocket): String? = null

  /** For MockWebServer. This returns the inbound SNI names. */
  @SuppressLint("NewApi")

          message == "No session to resume." -> Type.Handshake
          message.startsWith("Consuming ") -> Type.Handshake
          message.startsWith("Produced ") -> Type.Handshake
          message.startsWith("Negotiated ") -> Type.Handshake
          message.startsWith("Found resumable session") -> Type.Handshake
          message.startsWith("Resuming session") -> Type.Handshake

            ) {
              val sslSocket = connection.socket() as SSLSocket
              println("Requested " + sslSocket.sslParameters.applicationProtocols.joinToString())
              println("Negotiated " + sslSocket.applicationProtocol)
            }
          },
        )
        .build()

    val request =
      Request.Builder()
        .url("https://www.google.com")
        .build()

	options, err := optionsForTransform(mediaTypeOptions, req)
	if err != nil {
		return nil, err
	}

	// negotiate for the stream serializer from the scope's serializer
	serializer, err := negotiation.NegotiateOutputMediaTypeStream(req, scope.Serializer, scope)
	if err != nil {
		return nil, err
	}

// Master Secret is not negotiated and thus we wish to fail all key-material
// export requests.
func noEKMBecauseNoEMS(label string, context []byte, length int) ([]byte, error) {
	return nil, errors.New("crypto/tls: ExportKeyingMaterial is unavailable when neither TLS 1.3 nor Extended Master Secret are negotiated; override with GODEBUG=tlsunsafeekm=1")
}