setPaymentChangeable example

$orderRouteResponse = $this->getOrder($request, $salesChannelContext);

        /** @var OrderEntity $order */
        $order = $orderRouteResponse->getOrders()->first();

        if ($this->isOrderPaid($order)) {
            throw OrderException::orderAlreadyPaid($order->getId());
        }

        $page->setOrder($order);
        $page->setPaymentChangeable($this->isPaymentChangeable($orderRouteResponse, $page));
        $page->setPaymentMethods($this->getPaymentMethods($salesChannelContext, $request, $order));
        $page->setDeepLinkCode($request->get('deepLinkCode'));

        $this->eventDispatcher->dispatch(
            new AccountEditOrderPageLoadedEvent($page, $salesChannelContext, $request)
        );

        return $page;
    }

    private function getOrder(Request $request, SalesChannelContext $context): OrderRouteResponse
    {