// the call, but they may be accessed by other threads for duplex requests.

  /** True if this call still has a request body open. */
  private var requestBodyOpen = false

  /** True if this call still has a response body open. */
  private var responseBodyOpen = false

  /** True if there are more exchanges expected for this call. */
  private var expectMoreExchanges = true

      // current call to Source.read() has requested.
      try {
        val upstreamBytesRead = upstream!!.read(upstreamBuffer, bufferMaxSize)

        // If we've exhausted upstream, we're done.
        if (upstreamBytesRead == -1L) {
          commit(upstreamPos)
          return -1L
        }

        // Update this source and prepare this call's result.

## Version 4.0.1

_2019-07-10_

 *  Fix: Tolerate null-hostile lists in public API. Lists created with `List.of(...)` don't like it
    when you call `contains(null)` on them!
 *  Fix: Retain binary-compatibility in `okhttp3.internal.HttpHeaders.hasBody()`. Some unscrupulous
    coders call this and we don't want their users to suffer.


## Version 4.0.0

_2019-06-26_

        noNewExchangesEvent = !noNewExchanges
        noNewExchanges = true

        // If this route hasn't completed a call, avoid it for new connections.
        if (successCount == 0) {
          if (e != null) {
            connectFailed(call.client, route, e)
          }
          routeFailureCount++
        }
      }

      Unit
    }

    if (noNewExchangesEvent) {

    server.requestClientAuth()
    server.enqueue(
      MockResponse.Builder()
        .body("abc")
        .build(),
    )
    val call = client.newCall(Request.Builder().url(server.url("/")).build())
    val response = call.execute()
    assertThat(response.handshake!!.peerPrincipal)
      .isEqualTo(X500Principal("CN=Local Host"))
    assertThat(response.handshake!!.localPrincipal)

    fastFallback: Boolean = false,
    call: RealCall = this.call,
  ): RouteSelector {
    return RouteSelector(
      address = address,
      routeDatabase = routeDatabase,
      fastFallback = fastFallback,
      connectionUser = CallConnectionUser(call, ConnectionListener.NONE, newChain(call)),
    )
  }

  private fun newChain(call: RealCall): RealInterceptorChain {
    return RealInterceptorChain(

        OkHttpClient.Builder()
          .eventListenerFactory(
            clientTestRule.wrap(
              object : EventListener() {
                override fun connectionAcquired(
                  call: Call,
                  connection: Connection,
                ) {
                  socketClass = connection.socket().javaClass.name
                }
              },
            ),
          )

    )
  }

  override fun connectTcp(): ConnectResult {
    check(rawSocket == null) { "TCP already connected" }

    var success = false

    // Tell the call about the connecting call so async cancels work.
    user.addPlanToCancel(this)
    try {
      user.connectStart(route)

      connectSocket()
      success = true
      return ConnectResult(plan = this)

  /** Returns the HTTP headers. */
  @get:JvmName("headers") val headers: Headers,
  /**
   * Returns a non-null value if this response was passed to [Callback.onResponse] or returned
   * from [Call.execute]. Response bodies must be [closed][ResponseBody] and may
   * be consumed only once.
   *
   * This always returns null on responses returned from [cacheResponse], [networkResponse],
   * and [priorResponse].
   */

        it.proceed(it.request())
      }
      .build()
  }

  private fun makeRequest(client: OkHttpClient): Handshake {
    val call = client.newCall(Request(server.url("/")))
    return call.execute().use { it.handshake!! }
  }