svoid test_PersistentManagedObjects_v1() {
  new ManagedIntObjects_v1 mem;
  PersistentManagedObjects_v1<ManagedString> pm = new(mem, addr -> ManagedString.load(mem, addr));
  ManagedString s = pm.getUserData();
  assertNullVerbose("userData", s);
  pm.setUserData(ManagedString.create("Hello world"));
  s = pm.getUserData();
  assertEqualsVerbose("Hello world", str(s));
}