// what will return getUserCount() if called after processTransaction()

@Service
public class TransactionalPuzzlerService {

    @Autowired
    private UserRepository userRepository;

    @Transactional
    public void performTransactionalOperation() {
        userRepository.deleteAll();
        throw new RuntimeException("Oops! Something went wrong.");
    }

    public void processTransaction() {
        performTransactionalOperation();
    }

    public int getUserCount() {
        return userRepository.count();
    }
}