void onRequestDequeue() {
      requestDequeuedAtMs = time.milliseconds();
      networkMetrics.networkClientRequestQueueTime.update(requestDequeuedAtMs - requestQueuedAtMs,
          TimeUnit.MILLISECONDS);
    }
Actions to be done on dequeue of this request and ready to be sent
ambry-network/src/main/java/com/github/ambry/network/SocketNetworkClient.java