Class 'App\Http\Controllers\Session' not found in Laravel 5.2

I am using sessions in Laravel 5.2 . There is my Controller code:

if (Session::has('panier'))
{
     $panier = Session::get('panier');  
}

I try just to get a value from the session, and I got this error:

FatalErrorException in ProduitsController.php line 106: Class 'App\Http\Controllers\Session' not found

How can I resolve it?

From the error message:

Class 'App\Http\Controllers\Session' not found

I see that Laravel is searching the Session class in the current namespace: App\Http\Controllers

The problem is you don't have aliased the class from the global namespace: Session is a Facade, and all the facades are in the global namespace

To use the class from the global namespace, put:

use Session;

on top of your controller, after your namespace declaration

Alternatively, you can call the class from the global namespace with:

\Session::get('panier');