code: public static boolean openSession(SessionFactory sessionFactory) {
  	boolean participate = TransactionSynchronizationManager.hasResource(sessionFactory);
  	if (!participate) {
  	    Session session = SessionFactoryUtils.getSession(sessionFactory, true);
  	    session.setFlushMode(org.hibernate.FlushMode.ALWAYS);
  	    TransactionSynchronizationManager.bindResource(sessionFactory, new SessionHolder(session));
  	}
  	return participate;
      }
docs: /* return true if we "participate" to an existing session