static Map<O, Bool> autoCleanUp_list = newWeakHashMap();

static <A> A autoCleanUp(A a) {
  if (a != null)
    autoCleanUp_list.put(a, true);
  ret a;
}

static void cleanMeUp_autoCleanUp() {
  L l = cloneList(keys(autoCleanUp_list));
  autoCleanUp_list.clear();
  cleanUp(l);
}