static <A, B> Map<A, B> newDangerousWeakHashMap() {
  ret _registerDangerousWeakMap(synchroMap(new WeakHashMap));
}

// initFunction: voidfunc(Map) - is called initially, and after clearing the map
static <A, B> Map<A, B> newDangerousWeakHashMap(O initFunction) {
  ret _registerDangerousWeakMap(synchroMap(new WeakHashMap), initFunction);
}