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