pm.insert(mk2).get();
mk2.parent = mk1;
pm.update(mk2).get();
DiscoveryNoColumnMultipleKeys disc = new DiscoveryNoColumnMultipleKeys("disc1", mk1, mk2);
pm.insert(disc);
DiscoveryNoColumnMultipleKeys afterDisc = pm.getByKey(DiscoveryNoColumnMultipleKeys.class, disc.id).get();
assertNotNull(afterDisc);
assertEquals("disc1", afterDisc.name);
assertEquals(mk1.id1, afterDisc.mk1.id1);
assertEquals(mk1.id2, afterDisc.mk1.id2);
assertEquals(mk2.id1, afterDisc.mk2.id1);