ModifiedBottom b2 = new ModifiedBottom();
b2.setFoo(2);
pm.saveObject(b1);
pm.saveObject(b2);
pm.changeName(ModifiedTop.class, OriginalTop.class);
pm.changeName(ModifiedMiddle.class, OriginalMiddle.class);
pm.changeName(ModifiedBottom.class, OriginalBottom.class);
pm.updateSchema(OriginalBottom.class);
pm.close();