} 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() {

   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

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

    fun noNewExchanges()

    fun cancel()
  }

  companion object {
    /**