docs: private void completePreparingTransaction(TransactionId transactionId) {
      // Change ownership of the transaction to the local node and set its state to ROLLING_BACK and then roll it back.
      completeTransaction(
          transactionId,
          TransactionState.PREPARING,
          info -> new TransactionInfo(localMemberId, TransactionState.ROLLING_BACK, info.participants),
          info -> info.state == TransactionState.ROLLING_BACK,
          (id, transactional) -> transactional.rollback(id))
          .whenComplete((result, error) -> {
            if (error != null) {
              error = Throwables.getRootCause(error);
              if (error instanceof TransactionException) {
                LOGGER.warn("Failed to complete transaction", error);
              } else {
                LOGGER.warn("Failed to roll back transaction " + transactionId);
              }
            }
          });
    }