HttpURLConnection.HTTP_PROXY_AUTH -> {
          nextRequest = route.address.proxyAuthenticator.authenticate(route, response)
            ?: throw IOException("Failed to authenticate with proxy")

          if ("close".equals(response.header("Connection"), ignoreCase = true)) {
            return nextRequest
          }
        }

        else -> throw IOException("Unexpected response code for CONNECT: ${response.code}")
      }