shutdown method

@override Future<void> shutdown()

Implementation

@override
Future<void> shutdown() async {
  for (final sub in _subscriptions) {
    try {
      await sub.cancel();
    } catch (e, stack) {
      _log.error(
        'Could not cancel subscription.',
        error: e,
        trace: stack,
      );
    }
  }
  _subscriptions.clear();
}