/** INTERNAL: Rollback the transaction on all child sessions. */
 protected void basicRollbackTransaction() throws DatabaseException {
   DatabaseException globalException = null;
   for (Iterator sessionEnum = getSessionsByName().values().iterator(); sessionEnum.hasNext(); ) {
     AbstractSession session = (AbstractSession) sessionEnum.next();
     try {
       session.rollbackTransaction();
     } catch (DatabaseException exception) {
       globalException = exception;
     }
   }
   if (globalException != null) {
     throw globalException;
   }
 }