Rectangle rect = new Rectangle(1000, 1);
Key<Rectangle> rectKey = ds.save(rect);
assertEquals(rectKey.getId(), rect.getId());
FacebookUser fbUser1 = new FacebookUser(1, "scott");
FacebookUser fbUser2 = new FacebookUser(2, "tom");
FacebookUser fbUser3 = new FacebookUser(3, "oli");
FacebookUser fbUser4 = new FacebookUser(4, "frank");
Iterable<Key<FacebookUser>> fbKeys = ds.save(fbUser1, fbUser2, fbUser3, fbUser4);
assertEquals(fbUser1.id, 1);
List<Key<FacebookUser>> fbUserKeys = new ArrayList<Key<FacebookUser>>();
for(Key<FacebookUser> key :fbKeys)