static AutoCloseable dm_timerWithFieldSecondsInterval_startNow(S field, Runnable r) {
  DynModule m = dm_current_mandatory();
  new Flag cancel;
  thread "Timer" {
    Long lastFired = null;
    while (licensed() && !cancel.isUp()) {
      if (lastFired != null) {
        long interval = toMS(toDouble(get(m, field)));
        if (interval <= 0) fail("Need delay > 0: " + field + " in " + m);
        sleepUntilSysTime(lastFired+interval);
      }
      lastFired = sysNow();
      if (licensed() && !cancel.isUp())
        callF(r);
    }
  }
  ret flagAsAutoCloseable(cancel);
}