Flutter bloc and null safety implementation

Question

I'm implementing Null Safety to Bloc Patter in flutter, everything was ok, but when I tried to instance bloc in my widgets, I got an error "Null check operator used on a null value" The error cames from this section on my bloc event

class LoginEvent extends InheritedWidget{
  final LoginBloc loginBloc = LoginBloc();

  LoginEvent({required Widget child}) : super(child: child);
  // This function has the error
  static LoginBloc of(BuildContext context){
    return context.dependOnInheritedWidgetOfExactType<LoginEvent>()!.loginBloc;
  }

  @override
  bool updateShouldNotify(covariant InheritedWidget oldWidget) => true;
}

If I delete the '!' the message that appears is "The property 'loginBloc' can't be unconditionally accessed because the receiver can be 'null'."

This is my bloc class

class LoginBloc with LoginState{
  final _emailController = BehaviorSubject<String>();
  final _passwordController = BehaviorSubject<String>();

  Stream<String>get emailStream => _emailController.stream.transform(checkEmail);
  Stream<String>get passwordStream => _passwordController.stream.transform(checkEmail);

  Stream<bool> get formValidStream => Rx.combineLatest2(emailStream,passwordStream, (e,p) => true);

  Function(String) get changeEmail => _emailController.sink.add;
  Function(String) get changePassword => _passwordController.sink.add;

  String get email => _emailController.value;
  String get password => _passwordController.value;

  dispose(){
    _emailController.close();
    _passwordController.close();
  }
}

Fast preview of how it is called

  @override
  Widget build(BuildContext context) {
    var height =
        MediaQuery.of(context).size.height - MediaQuery.of(context).padding.top;
    var space = height > 650 ? DesignSpacings.spaceM : DesignSpacings.spaceS;
    
    final bloc = LoginEvent.of(context); // if this line is commented the app shows the widget again

    return Card(...);
  }

Solution

You can change the symbol '!' to '?'.