// returns last value
static <A> A printPolledValueUntilPredicateOrTimeout(
    IF0<A> makeValue,
    IPred<A> pred,
    double timeout,
    int interval default 100) {
  Timeout timeOut = new(timeout);
  A a = null;
  while (!timeOut!) {
    a = makeValue!;
    if (pred != null && pred.get(a))
      break;
    else
      sleep(interval);
  }
  ret a;
}