未声明模型，会报错

<?php  
//这里不声明的话，下面的Status会报错
use app\Models\Status
.  .  .  
class  StatusesController  extends  Controller  
{ 
    .  .  . 
    public  function  destroy(Status $status)  
    {  
        $this->authorize('destroy',  $status);  
        $status->delete();  
        session()->flash('success',  '微博已被成功删除！'); 
        return  redirect()->back();  
    }  
}