### Question:
CategoryServiceImpl implements CategoryService { @Override public List<ProductCategory> findByCategoryTypeIn(List<Integer> categoryTypeList) { return repository.findByCategoryTypeIn(categoryTypeList); }  @Override Optional<ProductCategory> findById(Integer categoryId); @Override List<ProductCategory> findAll(); @Override List<ProductCategory> findByCategoryTypeIn(List<Integer> categoryTypeList); @Override ProductCategory save(ProductCategory productCategory); @Override void delete(Integer categoryId);  }### Answer:
@Test public void findByCategoryTypeIn() { List<ProductCategory> productCategoryList = categoryService.findByCategoryTypeIn(Arrays.asList(1,2,3)); Assert.assertNotEquals(0,productCategoryList.size()); }