class SourceTrackingEventScheduler extends TypedEventScheduler {

    @Override
    public Cancelable doAt(double time, Runnable r, String description, boolean isDaemon) {
        MutableCancelableHolder cancelableHolder = new MutableCancelableHolder(r, description);
        doAt(time, isDaemon, cancelableHolder);
        return cancelableHolder;
    }

    public  SourceTrackingEventScheduler(SourceSchedulerTracker tracker, EventSchedulerType type, SimpleDiscreteEventScheduler backingScheduler);

}