static int mapMethodLike jfind_check(S checkToken, L<S> tok, S in) {
  ret jfind_check(checkToken, tok, in, null);
}

static int mapMethodLike jfind_check(S checkToken, L<S> tok, S in, O condition) {
  if (isIndexedList(tok) && !tok.contains(checkToken)) ret -1;
  ret jfind(tok, in, condition);
}