docs: public boolean txnRollbackPoll(long itemId, boolean backup) {
          TxQueueItem item = txMap.remove(itemId);
          if (item == null) {
              return false;
          }
  
          if (backup) {
              getBackupMap().put(itemId, item);
          } else {
              addTxItemOrdered(item);
          }
          cancelEvictionIfExists();
          return true;
      }