static <A> L<A> sortedDesc(Collection<A> c, O comparator) {
  L<A> l = cloneList(c);
  sort(l, makeReversedComparator(comparator));
  ret l;
}

static <A> L<A> sortedDesc(Collection<A> c, Comparator<A> comparator) {
  L<A> l = cloneList(c);
  sort(l, makeReversedComparator(comparator));
  ret l;
}

// TODO: should use a reverse comparator to keep sort stable
static <A> L<A> sortedDesc(Collection<A> c) {
  L<A> l = cloneList(c);
  sort(l);
  Collections.reverse(l);
  ret l;
}