dispose method
Implementation
Future<void> dispose() async {
_disposed = true;
_messageSubscription?.cancel();
_connectionStatusSubscription?.cancel();
_transactionUpdateController.close();
_initialConnectionController.close();
_oneOffQueryResultController.close();
_subscribeAppliedController.close();
_unsubscribeAppliedController.close();
_subscriptionErrorController.close();
_reducerResultController.close();
_procedureResultController.close();
reducerEmitter.dispose();
await _mutationSyncer?.dispose();
}