This project is great. i want to know how to use usecase

[est7]

My code is like this

class InitChatListUsecase {
  final IChatRepository repository;

  InitChatListUsecase({required this.repository});

  Future<Result<List<ChatModel>>> call() {
    return repository.getAllChatList();
  }
}

The code in the project looks like this

@riverpod
class DeleteTodoUseCaseImpl extends _$DeleteTodoUseCaseImpl
    implements DeleteTodoUseCase {
  @override
  Future<void> build(final int id) {
    final TodosRepository repository =
        ref.read(todosRepositoryImplProvider.notifier);
    return repository.deleteTodo(id);
  }
}

I want to know why Usecase is used as “StateNotifier” ?I'm a fresh on Riverpod, hope you can tell me about it