addOnErrorEventListener method Null safety

StreamSubscription addOnErrorEventListener(
  1. dynamic onError(
    1. ErrorEvent event
    )
)

Adds an event handler which gets executed each time notifyError is called.

Implementation

StreamSubscription addOnErrorEventListener(
    Function(ErrorEvent event) onError) {
  final newSubscription = _errorController.stream.listen(onError);
  _subscriptions.add(newSubscription);
  return newSubscription;
}