static <A> A persistentObject(S name, Class<? extends A> makeDefaultObject) {
  ret persistentObject(name, (O) makeDefaultObject);
}

// makeDefaultObject: (func -> A) or Class
static <A> A persistentObject(S name, O makeDefaultObject) {
  IVar<A> var = persistentVar(name);
  if (!var.has()) var.set((A)
    (makeDefaultObject instanceof Class ? nu((Class) makeDefaultObject) : callF(makeDefaultObject)));
  ret var!;
}

Began life as a copy of #1009539