docs: public void txnPollBackupReserve(long itemId, String transactionId) {
          QueueItem item = getBackupMap().remove(itemId);
          if (item != null) {
              txMap.put(itemId, new TxQueueItem(item).setPollOperation(true).setTransactionId(transactionId));
              return;
          }
          if (txMap.remove(itemId) == null) {
              logger.warning("Poll backup reserve failed, itemId: " + itemId + " is not found");
          }
      }