var nextRequest = tunnelRequest!!
    // Make an SSL Tunnel on the first message pair of each SSL + proxy connection.
    val url = route.address.url
    val requestLine = "CONNECT ${url.toHostHeader(includeDefaultPort = true)} HTTP/1.1"
    while (true) {
      val tunnelCodec =
        Http1ExchangeCodec(
          // No client for CONNECT tunnels:
          client = null,
          carrier = this,

   * That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

    fun trackFailure(
      call: RealCall,
      e: IOException?,
    )

     *   <li>TRACE - Echoes back the received request, used for debugging.</li>
     *   <li>CONNECT - Converts the request connection to a transparent TCP/IP tunnel.</li>
     * </ul>
     */
    public enum Method {
        /**
         * HTTP GET method.
         */
        GET,
        /**
         * HTTP POST method.
         */
        POST,

    }

    /**
     * Respond to `CONNECT` requests until a non-tunnel response is peeked. Returns true if further
     * calls should be attempted on the socket.
     */
    @Throws(IOException::class, InterruptedException::class)
    private fun processTunnelRequests(): Boolean {
      if (!dispatcher.peek().inTunnel) return true // No tunnel requests.

      val socket = MockWebServerSocket(raw)
      while (true) {

              .build(),
        ),
      )
    val response = call.execute()
    assertThat(response.isSuccessful).isTrue()

    server.takeRequest() // Discard the CONNECT tunnel.
    return server.takeRequest()
  }

_2022-06-08_

 *  Fix: Change how `H2_PRIOR_KNOWLEDGE` works with HTTP proxies. Previously OkHttp assumed the
    proxy itself was a prior knowledge HTTP/2 server. With this update, OkHttp attempts a `CONNECT`
    tunnel just as it would with HTTPS. For prior knowledge with proxies OkHttp's is now consistent
    with these curl arguments:

    ```
    curl \
      --http2-prior-knowledge \
      --proxy localhost:8888 \

     * doing HTTPS through an HTTP proxy, or HTTP/2 prior knowledge through an HTTP proxy.
     *
     * When a new connection is received, all in-tunnel responses are served before the connection is
     * upgraded to HTTPS or HTTP/2.
     */
    public fun inTunnel(): Builder =
      apply {
        removeHeader("Content-Length")
        inTunnel = true

      implements Funnel<Iterable<? extends E>> {
    private final Funnel<E> elementFunnel;

    SequentialFunnel(Funnel<E> elementFunnel) {
      this.elementFunnel = Preconditions.checkNotNull(elementFunnel);
    }

    @Override
    public void funnel(Iterable<? extends E> from, PrimitiveSink into) {
      for (E e : from) {
        elementFunnel.funnel(e, into);
      }
    }

      implements Funnel<Iterable<? extends E>> {
    private final Funnel<E> elementFunnel;

    SequentialFunnel(Funnel<E> elementFunnel) {
      this.elementFunnel = Preconditions.checkNotNull(elementFunnel);
    }

    @Override
    public void funnel(Iterable<? extends E> from, PrimitiveSink into) {
      for (E e : from) {
        elementFunnel.funnel(e, into);
      }
    }

    val get = server.takeRequest()
    assertThat(get.requestLine).isEqualTo("GET /foo HTTP/1.1")
    assertThat(get.headers["Proxy-Authorization"]).isNull()
  }

  // Don't disconnect after building a tunnel with CONNECT
  // http://code.google.com/p/android/issues/detail?id=37221
  @Test
  fun proxyWithConnectionClose() {
    server.useHttps(handshakeCertificates.sslSocketFactory())
    server.enqueue(