Group By no Hibernate

Pessoal, alguém sabe me dizer como fazer um group by no critério do hibernate?

abs,

Felipe

Com HQL:
http://www.hibernate.org/hib_docs/reference/en/html/queryhql.html

Com Criteria (no item 15.7. Projections, aggregation and grouping)
http://www.hibernate.org/hib_docs/reference/en/html/querycriteria.html

[]s
Eduardo