如何去掉这个错误提示信息？

    public function index(){
        try{
            \DB::connection()->enableQueryLog();
            $where = [];
            $where['id'] = 44;
            $article = Articles::with("articles_class")->where($where)->get();
            foreach ($article as $k=>$v) {
                $v->article_desc = 3456;
                $v->save();
                if($v['id']==44){
                    $class = $v->articles_class;
                    $class->class_name = "class_name";
                    $class->save();
                }
            }
            $queries = \DB::getQueryLog();
            return Tools::jsonReturn(0,'ok',['article'=>$article,'sql'=>$queries]);
        }catch (\Exception $e){
            return Tools::jsonReturn(123,$e->getMessage());
        }
    }

程序可以正常执行，但是在$class->save();这里，phpstorm提示Method 'save' not found，如何消除这个错误？