function __construct(Pixie $pixie)
 {
     $this->pixie = $pixie;
     Session::checkSessionStarted();
     if (!is_array($_SESSION['cart_service'])) {
         $_SESSION['cart_service'] = ['cart' => null, 'items' => [], 'addresses' => [], 'shipping_address' => null, 'billing_address' => null, 'shipping_address_object' => null, 'billing_address_object' => null, 'params' => [], 'removed_addresses' => [], 'last_step' => Cart::STEP_OVERVIEW];
         $this->reset();
     }
 }