/**
  * 根据id找分类对象
  * @param $id
  * @return ShopTopicCategory
  * @throws DeepInException
  */
 protected function find($id)
 {
     $category = ShopTopicCategory::find($id);
     if ($category instanceof ShopTopicCategory) {
         return $category;
     }
     throw new DeepInException("找不到专题分类id为" . $id . "的数据~!");
 }