static Map<S, L<Int>> lcRenumberTopLevelEncodings(LineCompCompressor lc) {
  new LinkedHashMap<S, L<Int>> out;
  new Map<Int> map;
  for (S file, L<Int> l : lc.finalEncodings) {
    new L<Int> l2;
    for (int i : l) {
      Int j = map.get(i);
      if (j == null)
        map.put(i, j = l(map)+1);
      l2.add(j);
    }
    out.put(file, l2);
  }
  ret out;
}