).socket(exchange.upgradeToSocket())
              .build()
          }

          // This is not an upgrade response.
          else -> {
            val responseBody = exchange.openResponseBody(response)
            response
              .newBuilder()
              .body(responseBody)
              .trailers(
                object : TrailersSource {

      throw e
    }
  }

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

  @Throws(IOException::class)
  fun openResponseBody(response: Response): ResponseBody {
    try {
      val contentType = response.header("Content-Type")
      val contentLength = codec.reportedContentLength(response)