code: void recordDroppedRequest(String token) {
      callsStartedUpdater.getAndIncrement(this);
      callsFinishedUpdater.getAndIncrement(this);
  
      synchronized (this) {
        LongHolder holder;
        if ((holder = callsDroppedPerToken.get(token)) == null) {
          callsDroppedPerToken.put(token, (holder = new LongHolder()));
        }
        holder.num++;
      }
    }
docs: Records that a request has been dropped as instructed by the remote balancer.