static <B, A extends Map<B, ? super S>> L<A> sortByMapKeyAlphaNum(Iterable<A> c, final B key) {
  L<A> l = cloneList(c);
  sort(l, new Comparator<A>() {
    public int compare(A a, A b) {
      ret cmpAlphaNum((S) mapGet((Map) a, (O) key), (S) mapGet((Map) b, (O) key));
    }
  });
  ret l;
}