waitForDismiss method
Implementation
@override
Future<Reward?> waitForDismiss() async {
Reward? reward;
_eventListener?.waitFor([_FullScreenAdCallbackName.onRewarded]).then(
(result) => reward = Reward._(result['type'], result['amount']));
await _eventListener?.waitFor([_FullScreenAdCallbackName.onAdDismissed]);
return reward;
}