public function loadPayPalOrder()
    {
        $orderId = \OxidEsales\Eshop\Core\Registry::getSession()->getVariable("sess_challenge");

        // if order is not created yet - generating it
        if ($orderId === null) {
            $orderId = \OxidEsales\Eshop\Core\UtilsObject::getInstance()->generateUID();
            $this->setId($orderId);
            $this->save();
            \OxidEsales\Eshop\Core\Registry::getSession()->setVariable("sess_challenge", $orderId);
        }

        return $this->load($orderId);
    }