private void scheduleExpiry(TransactionId txId, TimeUnit expiryTimeUnit) {
    if (suspendedTXTimeout < 0) {
      if (logger.isDebugEnabled()) {
        logger.debug("TX: transaction: {} not scheduled to expire", txId);
      }
      return;
    }
    SystemTimerTask task = new TXExpiryTask(txId);
    if (logger.isDebugEnabled()) {
      logger.debug("TX: scheduling transaction: {} to expire after:{}", txId, suspendedTXTimeout);
    }
    cache.getCCPTimer().schedule(task,
        TimeUnit.MILLISECONDS.convert(suspendedTXTimeout, expiryTimeUnit));
    expiryTasks.put(txId, task);
  }
schedules the transaction to expire after {@link #suspendedTXTimeout}

@param expiryTimeUnit the time unit to use when scheduling the expiration
geode-core/src/main/java/org/apache/geode/internal/cache/TXManagerImpl.java