code: @Override
      public void rollback() throws IllegalStateException, SystemException
      {
          for (ResourceManager implementor : implementors)
          {
              if (implementor != null)
              {
                  implementor.doRollback();
                  status = Status.STATUS_ROLLEDBACK;
              }
          }
      }
docs: /*
  (non-Javadoc)
  
  @see javax.transaction.Transaction#rollback()