registerTheme example

public function resetTemplate(Shop $shop): void
    {
        $template = $shop->getTemplate();
        if (!$template instanceof Template) {
            return;
        }

        $localeName = $shop->getLocale()->toString();

        if ($template->getVersion() === 3) {
            $this->registerTheme($template);
        } else {
            throw new RuntimeException(sprintf('Tried to load unsupported template version %s for template: %s', $template->getVersion(), $template->getName()));
        }

        $this->container->get(Enlight_Template_Manager::class)->setCompileId(
            sprintf('frontend_%s_%s_%s', $template->toString(), $localeName, $shop->getId())
        );
    }

    private function registerTheme(Template $template): void
    {