code: public void recordResourceRequestQueueLength(SocketDestination dest, int queueLength) {
          if(dest != null) {
              getOrCreateNodeStats(dest).recordResourceRequestQueueLength(null, queueLength);
              recordResourceRequestQueueLength(null, queueLength);
          } else {
              this.resourceRequestQueueLengthHistogram.insert(queueLength);
              checkMonitoringInterval();
          }
      }
docs: Record the resource request queue length
  
  @param dest Destination of the socket for which resource request is
  enqueued. Will actually record if null. Otherwise will call this
  on self and corresponding child with this param null.
  @param queueLength The number of entries in the "asynchronous" resource
  request queue.