docs: public void handleQueryMessage(final long senderHSId, long requestId, long gapStart) {
              m_es.execute(new Runnable() {
                  @Override
                  public void run() {
                      long lastSeq = Long.MIN_VALUE;
                      Pair<Long, Long> range = m_gapTracker.getRangeContaining(gapStart);
                      if (range != null) {
                          lastSeq = range.getSecond();
                      }
                      sendQueryResponse(senderHSId, requestId, lastSeq);
                  }
              });
      }