svoid tok_forUnnull(LS tok) {
  int i;
  while ((i = jfind(tok, "for unnull (")) >= 0) {
    int argsFrom = i+4;
    int iColon = indexOf(tok, i, ":");
    int iClosing = tok_findEndOfForExpression(tok, i);
    clearTokens(tok, i+2, i+4);
    tokPrepend(tok, iColon+2, "unnull(");
    tokPrepend(tok, iClosing, ")");
    reTok(tok, i+2, iClosing+1);
  }
}