OrderPaymentMethodChangedEvent example

$changedOrder = $this->loadOrder($order->getId(), $salesChannelContext);
        $transactions = $changedOrder->getTransactions();
        if ($transactions === null || ($transaction = $transactions->get($transactionId)) === null) {
            if (Feature::isActive('v6.6.0.0')) {
                throw OrderException::orderTransactionNotFound($transactionId);
            }

            throw new UnknownPaymentMethodException($paymentMethodId);
        }

        $event = new OrderPaymentMethodChangedEvent(
            $changedOrder,
            $transaction,
            $context,
            $salesChannelContext->getSalesChannelId()
        );
        $this->eventDispatcher->dispatch($event);
    }

    private function validateRequest(SalesChannelContext $salesChannelContext, string $paymentMethodId): void
    {
        $paymentRequest = new Request();