public void alterarLista(List<T> ts) throws ValidacaoException {
        try {
            transacao = session.beginTransaction();
            session.clear();
            for (T t : ts) {
                session.merge(t);
            }
            transacao.commit();
        } catch (HibernateException e) {
            transacao.rollback();
            throw new ValidacaoException(e.getMessage());
        }
    }