add method

Implementation

CountdownHandle add(CountdownOptions opts) {
  final id = nextId();
  enqueue(CountdownTask(
    id: id,
    total: opts.duration,
    onUpdate: opts.onUpdate,
    onComplete: opts.onComplete,
    threshold: opts.threshold,
    onThreshold: opts.onThreshold,
    onReady: opts.onReady,
    onStart: opts.onStart,
    onCancel: opts.onCancel,
    onPause: opts.onPause,
    onResume: opts.onResume,
  ));
  return CountdownHandle._(id, this);
}