Laravel 4：无法访问包类中的Auth实例

I have this class in a workbench package:

class SomeClass{

//Constructor
function __construct(){

    $isAuth = Auth::check();   

    }

But it gives me following error:

Class 'vendor\pachage\Auth' not found

Is this a namespace issue? I am using the following namespace:

namespace vendor\pachage;

You need Fully qualified name, add a backslash:

\Auth::check();