try {
      val result = codec.readResponseHeaders(expectContinue)
      result?.initExchange(this)
      return result
    } catch (e: IOException) {
      eventListener.responseFailed(call, e)
      trackFailure(e)
      throw e
    }
  }

  fun responseHeadersEnd(response: Response) {
    eventListener.responseHeadersEnd(call, response)
  }

  @Throws(IOException::class)