} catch (e: IOException) {
      eventListener.requestFailed(call, e)
      trackFailure(e)
      throw e
    }
  }

  @Throws(IOException::class)
  fun finishRequest() {
    try {
      codec.finishRequest()
    } catch (e: IOException) {
      eventListener.requestFailed(call, e)
      trackFailure(e)
      throw e
    }
  }

  fun responseHeadersStart() {

  @Throws(IOException::class)
  fun flushRequest()

  /** Flush the request to the underlying socket and signal no more bytes will be transmitted. */
  @Throws(IOException::class)
  fun finishRequest()

  /**
   * Parses bytes of a response header from an HTTP transport.
   *
   * @param expectContinue true to return null if this is an intermediate response with a "100"

            exchange.noNewExchangesOnConnection()
          }
        }
      } else {
        exchange.noRequestBody()
      }

      if (requestBody == null || !requestBody.isDuplex()) {
        exchange.finishRequest()
      }
    } catch (e: IOException) {
      if (e is ConnectionShutdownException) {
        throw e // No request was sent so there's no response to read.
      }
      if (!exchange.hasFailure) {

    stream!!.writeTimeout().timeout(chain.writeTimeoutMillis.toLong(), TimeUnit.MILLISECONDS)
  }

  override fun flushRequest() {
    http2Connection.flush()
  }

  override fun finishRequest() {
    stream!!.getSink().close()
  }

  override fun readResponseHeaders(expectContinue: Boolean): Response.Builder? {
    val stream = stream ?: throw IOException("stream wasn't created")

    check(state == STATE_CLOSED) { "too early; can't read the trailers yet" }
    return trailers ?: EMPTY_HEADERS
  }

  override fun flushRequest() {
    sink.flush()
  }

  override fun finishRequest() {
    sink.flush()
  }

  /** Returns bytes of a request header for sending on an HTTP transport. */
  fun writeRequest(
    headers: Headers,
    requestLine: String,
  ) {

      sink.timeout().timeout(writeTimeoutMillis.toLong(), TimeUnit.MILLISECONDS)
      tunnelCodec.writeRequest(nextRequest.headers, requestLine)
      tunnelCodec.finishRequest()
      val response =
        tunnelCodec.readResponseHeaders(false)!!
          .request(nextRequest)
          .build()
      tunnelCodec.skipConnectBody(response)

      when (response.code) {