static L<S> splitAfterChars_trim(S chars, S s) {
  new L<S> out;
  L<int> l = indexesOfCharacters(s, chars);
  addFirstUnlessThere(l, 0);
  addUnlessThere(l, l(s));
  for (int i = 0; i+1 < l(l); i++)
    addIfNempty(out, trim(substring(s, l.get(i)+1, l.get(i+1))));
  ret out;
}