tryTransition example

$this->validatePaymentState($order);

        $this->setPaymentMethod($paymentMethodId, $order, $context);

        return new SetPaymentOrderRouteResponse();
    }

    private function setPaymentMethod(string $paymentMethodId, OrderEntity $order, SalesChannelContext $salesChannelContext): void
    {
        $context = $salesChannelContext->getContext();

        if ($this->tryTransition($order, $paymentMethodId, $context)) {
            return;
        }

        $initialState = $this->initialStateIdLoader->get(OrderTransactionStates::STATE_MACHINE);

        $transactionAmount = new CalculatedPrice(
            $order->getPrice()->getTotalPrice(),
            $order->getPrice()->getTotalPrice(),
            $order->getPrice()->getCalculatedTaxes(),
            $order->getPrice()->getTaxRules()
        );