### Question:
ProductServiceImpl implements ProductService { @Override public Result<List<CategoryEntity>> findCategorys(CategoryQueryReq categoryQueryReq) { List<CategoryEntity> categoryEntityList = categoryDAO.findCategorys(categoryQueryReq); if (CollectionUtils.isEmpty(categoryEntityList)){ throw new CommonBizException(ExpCodeEnum.CATEGORY_SELECT_FAIL); } return Result.newSuccessResult(categoryEntityList); }  @Override Result createProduct(ProdInsertReq prodInsertReq); @Override Result updateProduct(ProdUpdateReq prodUpdateReq); @Override Result<List<ProductEntity>> findProducts(ProdQueryReq prodQueryReq); @Override Result createCategoty(CategoryEntity categoryEntity); @Override Result modifyCategory(CategoryEntity categoryEntity); @Override Result deleteCategory(String categoryId); @Override Result createBrand(BrandInsertReq brandInsertReq); @Override Result modifyBrand(BrandInsertReq brandInsertReq); @Override Result<List<CategoryEntity>> findCategorys(CategoryQueryReq categoryQueryReq); @Override Result<List<BrandEntity>> findBrands(BrandQueryReq brandQueryReq); void checkBrandParam(BrandInsertReq brandInsertReq);  }### Answer:
@Test public void testFindCategorys(){ CategoryQueryReq categoryQueryReq = new CategoryQueryReq(); categoryQueryReq.setParentId("d87b243d99e341d2b4af8e72bb49f6ad"); productService.findCategorys(categoryQueryReq); }