static <A, B> Map<A, B> zipTwoListsToOrderedMap(L<A> l1, L<B> l2) {
  int n = min(l(l1), l(l2));
  new LinkedHashMap<A, B> map;
  for i to n: map.put(l1.get(i), l2.get(i));
  ret map;
}