mergeConfiguration example

        return $this->pageSize;
    }

    public function setPageSize(?string $pageSize): void
    {
        $this->pageSize = $pageSize;
    }

    public function merge(array $config): self
    {
        return DocumentConfigurationFactory::mergeConfiguration($this, $config);
    }

    public function buildName(): string
    {
        return $this->filenamePrefix . $this->documentNumber . $this->filenameSuffix;
    }

    public function getApiAlias(): string
    {
        return 'document_configuration';
    }
}

    private function __construct()
    {
        // Factory is Static     }

    public static function createConfiguration(array $specificConfig, ?DocumentBaseConfigEntity ...$configs): DocumentConfiguration
    {
        $configs = array_filter($configs);
        $documentConfiguration = new DocumentConfiguration();
        foreach ($configs as $config) {
            $documentConfiguration = static::mergeConfiguration($documentConfiguration, $config);
        }
        $documentConfiguration = static::mergeConfiguration($documentConfiguration, $specificConfig);

        return $documentConfiguration;
    }

    public static function mergeConfiguration(DocumentConfiguration $baseConfig, DocumentBaseConfigEntity|DocumentConfiguration|array $additionalConfig): DocumentConfiguration
    {
        $additionalConfigArray = [];
        if (\is_array($additionalConfig)) {
            $additionalConfigArray = $additionalConfig;
        }

public function testLoadSalesChannelConfig(): void
    {
        $base = $this->getBaseConfig('invoice');

        $globalConfig = DocumentConfigurationFactory::createConfiguration([
            'companyName' => 'Test corp.',
            'displayCompanyAddress' => true,
        ], $base);

        $this->upsertBaseConfig($globalConfig->jsonSerialize(), InvoiceRenderer::TYPE);

        $salesChannelConfig = DocumentConfigurationFactory::mergeConfiguration($globalConfig, [
            'companyName' => 'Custom corp.',
            'displayCompanyAddress' => false,
            'pageSize' => 'a5',
        ]);

        $salesChannelId = $this->salesChannelContext->getSalesChannel()->getId();
        $this->upsertBaseConfig($salesChannelConfig->jsonSerialize(), InvoiceRenderer::TYPE, $salesChannelId);

        $config = $this->documentConfigLoader->load(InvoiceRenderer::TYPE, $salesChannelId, $this->context);

        $config = $config->jsonSerialize();