}
    }

    return null
  }

  private fun <E : IOException?> timeoutExit(cause: E): E {
    if (timeoutEarlyExit) return cause
    if (!timeout.exit()) return cause

    val e = InterruptedIOException("timeout")
    if (cause != null) e.initCause(cause)
    @Suppress("UNCHECKED_CAST") // E is either IOException or IOException?
    return e as E
  }

  /**

  fun sendFrame(): Http2Writer {
    outFrames.add(OutFrame(frameCount++, bytesOut.size, false))
    return writer
  }

  /**
   * Shortens the last frame from its original length to `length`. This will cause the peer to
   * close the socket as soon as this frame has been written; otherwise the peer stays open until
   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {

  private val data = Buffer()
  private val random = Random(0)

  /**
   * Check all data as verified inside of the test. We do this in an AfterEachCallback so that
   * exceptions thrown from the test do not cause this check to fail.
   */
  @RegisterExtension
  val noDataLeftBehind =
    AfterEachCallback { context: ExtensionContext ->
      if (context.executionException.isPresent) return@AfterEachCallback

    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }
    // Check for the characters mentioned in the WHATWG Host parsing spec:

    redirect from one hostname to another, and where both hosts had common certificates.

 *  Fix: Don't fail on a redirect when a client has configured a 'trust everything' trust manager.
    Typically this would cause certain redirects to fail in debug and development configurations.


## Version 4.4.0

_2020-02-17_

 *  New: Support `canceled()` as an event that can be observed by `EventListener`. This should be

        assertThat(throwables!!.size).isEqualTo(1)
      }
    }
  }

  /**
   * When a pooled connection fails, don't blame the route. Otherwise pooled connection failures can
   * cause unnecessary SSL fallbacks.
   *
   * https://github.com/square/okhttp/issues/515
   */
  @Test
  fun sslFallbackNotUsedWhenRecycledConnectionFails() {
    server.useHttps(handshakeCertificates.sslSocketFactory())

      closeLater(ErrorCode.CANCEL)
      connection.sendDegradedPingLater()
    }

    override fun newTimeoutException(cause: IOException?): IOException {
      return SocketTimeoutException("timeout").apply {
        if (cause != null) {
          initCause(cause)
        }
      }
    }

    @Throws(IOException::class)
    fun exitAndThrowIfTimedOut() {

    // ConnectionSpec: we assume it is unreachable.
    e is InterruptedIOException -> false

    // If the problem was a CertificateException from the X509TrustManager, do not retry.
    e is SSLHandshakeException && e.cause is CertificateException -> false

    // e.g. a certificate pinning error.
    e is SSLPeerUnverifiedException -> false

    // Retry for all other SSL failures.
    e is SSLException -> true

    else -> false

    if (shutdown) return
    shutdown = true

    if (!started) return // Nothing to shut down.
    val serverSocket = this.serverSocket ?: return // If this is null, start() must have failed.

    // Cause acceptConnections() to break out.
    serverSocket.close()

    // Await shutdown.
    for (queue in taskRunner.activeQueues()) {
      if (!queue.idleLatch().await(5, TimeUnit.SECONDS)) {

    val data = ByteArray(1024 * 1024)
    var i = 0
    while (i < 1024) {
      try {
        out!!.write(data)
        out.flush()
        if (i == 513) {
          // pause slightly after half way to make result more predictable
          Thread.sleep(100)
        }
      } catch (e: IOException) {
        break
      }
      i++
    }
    // Halfway +/- 0.5%