static S selfLink() {
  ret getActualURI();
}

static S selfLink(S p1, O... params) {
  S uri;
  if (even(l(params)))
    uri = botLink(programID(), p1);
  else
    uri = getActualURI();
  ret uri + htmlQuery(litorderedmap(concatArrays(new O[] {p1}, params)));
}

static S selfLink(Map<S, S> params, L<S> keepFields, S... newValues) {
  new Map<S, S> map;
  for (S key : keepFields) {
    S val = params.get(key);
    if (val != null)
      map.put(key, val);
  }
  for (int i = 0; i+1 < l(newValues); i += 2) {
    S key = get(newValues, i);
    S val = get(newValues, i+1);
    if (empty(key)) continue;
    if (empty(val))
      map.remove(key);
    else
      map.put(key, val);
  }
  ret getActualURI() + htmlQuery(map);
}