public Tag adicionaOuBuscaTagComNome(String nome){
		String jpql = "select t from Tag t where t.nome=:pNome";
		TypedQuery<Tag> query = em.createQuery(jpql, Tag.class);
		query.setParameter("pNome", nome);
		Tag tag;
		try{
			tag = query.getSingleResult();
		}catch(NoResultException e){
			tag = new Tag();
			tag.setNome(nome);
			em.persist(tag);
		}
		return tag;
	}