### Question:
ProductServiceImpl implements ProductService { @Override public ProductInfo findOne(String productId) { return repository.findOne(productId); }  @Override ProductInfo findOne(String productId); @Override List<ProductInfo> findUpAll(); @Override Page<ProductInfo> findAll(Pageable pageable); @Override ProductInfo save(ProductInfo productInfo); @Override @Transactional void increaseStock(List<CartDTO> cartDTOList); @Override @Transactional void decreaseStock(List<CartDTO> cartDTOList); @Override ProductInfo onSale(String productId); @Override ProductInfo offSale(String productId);  }### Answer:
@Test public void findOne() throws Exception { ProductInfo productInfo = productService.findOne("123456"); Assert.assertEquals("123456", productInfo.getProductId()); }