Controller/Order/Save.php
private function clearOrderSession($order)
    {
        $this->checkoutSession->setLastOrderId($order->getId())
                              ->setLastRealOrderId($order->getIncrementId())
                              ->setLastOrderStatus($order->getStatus());
    }
private function clearOrderSession($order)
    {
        $this->checkoutSession->setLastOrderId($order->getId())
                              ->setLastRealOrderId($order->getIncrementId())
                              ->setLastOrderStatus($order->getStatus());
    }
private function clearOrderSession ( $ order ) { $ this -> checkoutSession -> setLastOrderId ( $ order -> getId ( ) ) -> setLastRealOrderId ( $ order -> getIncrementId ( ) ) -> setLastOrderStatus ( $ order -> getStatus ( ) ) ; }
Clear order session after successful order

@param Order $order

@return void
Clear order session after successful order