}

      exchange.responseHeadersEnd(response)

      val isUpgradeCode = code == HTTP_SWITCHING_PROTOCOLS
      if (isUpgradeCode && exchange.connection.isMultiplexed) {
        throw ProtocolException("Unexpected $HTTP_SWITCHING_PROTOCOLS code on HTTP/2 connection")
      }

      val isUpgradeResponse =
        isUpgradeCode &&
          "upgrade".equals(response.header("Connection"), ignoreCase = true)