code: public long checkPause() {
          if (pauseOnLongQueue &&
                  (getNumOfPendingMessages() > queue4Sink.remainingCapacity() ||
                  getNumOfPendingMessages() > MAX_PENDING_MESSAGES_TO_PAUSE)) {
              double throughputRate = Math.max(throughput.meanRate(), 1.0);
              return (long) (getNumOfPendingMessages() / throughputRate);
          } else {
              return 0;
          }
      }
docs: so, setting up minimum threshold as 1 message per millisecond