private function validateBrowserType(ContainerBuilder $container, string $valueType): void
    {
        if ($container->has(sprintf('netgen_content_browser.config.%s', $valueType))) {
            return;
        }

        throw new RuntimeException(
            sprintf(
                'Netgen Content Browser backend for "%s" value type does not exist.',
                $valueType
            )
        );
    }