pc.getStringRels().add(rel2);
pc.getStringRels().add(rel3);
OpenJPAEntityManager em = (OpenJPAEntityManager) currentEntityManager();
startTx(em);
em.persistAll(pc, rel1, rel2, rel3);
endTx(em);
endEm(em);
em = (OpenJPAEntityManager) currentEntityManager();
pc = em.find(OrderByEntity.class, 1L);