ds.put(grandChildEntity1);
Entity grandChildEntity2 =
new Entity(BidirectionalGrandchildListJPA.class.getSimpleName(), childEntity.getKey());
ds.put(grandChildEntity2);
BidirectionalChildListJPA child =
em.find(BidirectionalChildListJPA.class, KeyFactory.keyToString(childEntity.getKey()));
Query q = em.createQuery(
"select from " + BidirectionalGrandchildListJPA.class.getName() + " c where parent = :p");
q.setParameter("p", child);
@SuppressWarnings("unchecked")