static SS zipCodeTokensToCIMap_strict_withoutEquals(LS tok1, LS tok2) {
  int n = l(tok1);
  if (n != l(tok2)) null;
  SS map = ciMap();
  for (int i = 1; i < n; i += 2)
    if (!strictPutICIfKeyNotEqualToValue(map, tok1.get(i), tok2.get(i)))
      null;
  ret map;
}