code: public void recordSyncOpTimeNs(SocketDestination dest, long opTimeNs) {
          if(dest != null) {
              getOrCreateNodeStats(dest).recordSyncOpTimeNs(null, opTimeNs);
              recordSyncOpTimeNs(null, opTimeNs);
          } else {
              this.syncOpTimeRequestCounter.addRequest(opTimeNs);
          }
      }
docs: Record operation for sync ops time
  
  @param dest Destination of the socket to connect to. Will actually record
  if null. Otherwise will call this on self and corresponding child
  with this param null.
  @param opTimeUs The number of us for the op to finish