According to the EJB 3.0 Persistence specification, a generated primary key must
be available in @PostPersist methods. While this works pretty well as long as
the primary key is @Id, that is not working when the primary key is @EmbeddedId:
No instance of the primary key class is created.
I did not find a section of the specification that makes a distinction in this
situation between @Id and @EmbeddedId, so for me it looks like a violation of