### Question:
ProductServiceImpl implements ProductService { @Transactional(propagation=Propagation.REQUIRED) public List<Product> listProductByCategoryid(int categoryid) { return productMapper.listProductByCategoryid(categoryid); }  @Transactional(propagation=Propagation.REQUIRED) List<Product> listAllProduct(); @Transactional(propagation=Propagation.REQUIRED) List<Product> listProductByCategoryid(int categoryid); @Transactional(propagation=Propagation.REQUIRED) List<Product> listAllProductIncludeCategoryName(); void insertProduct(Product product); void updateProduct(Product product); Product findProductById(int id); List<Product> like(String name); List<Product> page(int pageNumber, int pageSize); List<Product> dynaQuerySql(Product product);  }### Answer:
@Test public void listProductByCategoryid(){ List<Product> listAllProduct = productService.listProductByCategoryid(2); for (Product product : listAllProduct) { System.out.println(product); } }