PaymentService example

$struct = new AsyncPaymentTransactionStruct($transaction, $order, '');
        $paymentStructFactory = $this->createMock(AbstractPaymentTransactionStructFactory::class);
        $paymentStructFactory->expects(static::once())->method('async')->willReturn($struct);

        $paymentHandler = $this->createMock(AsynchronousPaymentHandlerInterface::class);
        $paymentHandler->expects(static::once())->method('finalize')->with($struct, $request, $context);

        $paymentHandlerRegistry = $this->createMock(PaymentHandlerRegistry::class);
        $paymentHandlerRegistry->expects(static::once())->method('getAsyncPaymentHandler')->willReturn($paymentHandler);

        $paymentService = new PaymentService(
            $this->createMock(PaymentTransactionChainProcessor::class),
            $tokenFactory,
            $paymentHandlerRegistry,
            $transactionRepository,
            $this->createMock(OrderTransactionStateHandler::class),
            $this->createMock(LoggerInterface::class),
            $this->createMock(EntityRepository::class),
            $this->createMock(SalesChannelContextServiceInterface::class),
            $paymentStructFactory,
            $eventDispatcher
        );