Person p1 = d.createPerson().setName("p1");
Family f1 = d.createFamily().setName("f1");
p1.addFriendFamily(f1);
assertEquals(1,p1.getFriendFamilies().size());
assertEquals(1,f1.getFriendPersons().size());
d.dump("1");
d.commit();
d.dump("2");
p1 = d.getPerson(p1.id());
f1 = d.getFamily(f1.id());
assertEquals(1,p1.getFriendFamilies().size());