onSubscribeFail property Null safety

SubscribeFailCallback? onSubscribeFail

On subscribed fail

Implementation

SubscribeFailCallback? get onSubscribeFail => _onSubscribeFail;
void onSubscribeFail=(SubscribeFailCallback? cb)

Implementation

set onSubscribeFail(SubscribeFailCallback? cb) {
  _onSubscribeFail = cb;
  subscriptionsManager?.onSubscribeFail = cb;
}