generateCreditItems example

    public function testRender(
        array $possibleTaxes,
        array $creditPrices,
        ?\Closure $successCallback = null,
        ?\Closure $errorCallback = null,
        array $additionalConfig = []
    ): void {
        $cart = $this->generateDemoCart($possibleTaxes);
        $cart = $this->generateCreditItems($cart, $creditPrices);

        $orderId = $this->cartService->order($cart, $this->salesChannelContext, new RequestDataBag());

        $invoiceConfig = new DocumentConfiguration();
        $invoiceConfig->setDocumentNumber('1001');

        $operationInvoice = new DocumentGenerateOperation($orderId, FileTypes::PDF, $invoiceConfig->jsonSerialize());
        $result = $this->documentGenerator->generate(InvoiceRenderer::TYPE, [$orderId => $operationInvoice], $this->context)->getSuccess()->first();
        static::assertNotNull($result);
        $invoiceId = $result->getId();