PersistenceManager oldPM = oldPMF.getPersistenceManager();
MigratorOneToManyParent p = new MigratorOneToManyParent();
p.setName("First Parent");
MigratorOneToManyChild c = new MigratorOneToManyChild();
c.setName("Child 1");
p.addChild(c);
beginTxn();
oldPM.makePersistent(p);
commitTxn();
ObjectIdentity pId = (ObjectIdentity)oldPM.getObjectId(p);
ObjectIdentity cId = (ObjectIdentity)oldPM.getObjectId(c);