code: public boolean enlist(XAResource xaRes, int recoveryId)
                      throws RollbackException, IllegalStateException, SystemException
      {
          if (tc.isEntryEnabled())
              Tr.entry(tc, "enlist", new Object[] { xaRes, recoveryId });
  
          if (tx == null)
          {
              final String msg = "No transaction associated with this thread";
              final IllegalStateException ise = new IllegalStateException(msg);
              FFDCFilter.processException(ise, "com.ibm.tx.jta.impl.TranManagerImpl.enlist", "470", this);
              if (tc.isEntryEnabled())
                  Tr.exit(tc, "enlist", ise);
              throw ise;
          }
  
          boolean ret = false;
          try
          {
              ret = tx.enlistResource(xaRes, recoveryId);
          } finally
          {
              if (tc.isEntryEnabled())
                  Tr.exit(tc, "enlist", ret);
          }
          return ret;
      }
docs: that this class is managing.