private static boolean checkNoSendersGroupTransactionEvents(List<EntryEventImpl> callbacks,
      Cache cache) throws ServiceConfigurationError {
    for (String senderId : getSenderIdsForEvents(callbacks)) {
      GatewaySender sender = cache.getGatewaySender(senderId);
      if (sender != null && sender.mustGroupTransactionEvents()) {
        return false;
      }
    }
    return true;
  }
@param callbacks list of events belonging to a transaction

@return the last event of the transaction.
        If the regions to which the events belong do not have senders
        that group transactions it returns null.
        If the regions to which the
        events belong have different sets of senders that group transactions
        then it throws a ServiceConfigurationError exception.
geode-core/src/main/java/org/apache/geode/internal/cache/TXLastEventInTransactionUtils.java