code: @Override
      public String exportTransaction() throws SystemException {
  
          // blow up if there's no tran
          final UOWCoordinator uowCoord = _uowc.getUOWCoord();
          if (uowCoord == null || !uowCoord.isGlobal()) {
              throw new SystemException("No global transaction");
          }
  
          // TODO TransactionWrapper stuff
  
          // Suspend transaction association as we are going off server
          ((DistributableTransaction) uowCoord).suspendAssociation();
  
          return ((DistributableTransaction) uowCoord).getGlobalId();
      }
docs: /*
  (non-Javadoc)
  
  @see com.ibm.tx.remote.RemoteTransactionController#exportTransaction()