getCountryIsos example

        }

        if (!$request->request->has('config_shop_language')) {
            $request->request->set('config_shop_language', $this->supportedLanguages[$request->attributes->get('_locale')]);
        }

        return $this->renderInstaller(
            '@Installer/installer/shop-configuration.html.twig',
            [
                'error' => $error,
                'countryIsos' => $this->getCountryIsos($connection, $request->attributes->get('_locale')),
                'languageIsos' => $this->supportedLanguages,
                'currencyIsos' => $this->supportedCurrencies,
                'parameters' => $request->request->all(),
            ]
        );
    }

    /** * @return array<int, array{iso3: string, default: bool}> */
    private function getCountryIsos(Connection $connection, string $currentLocale): array
    {