getCurrentLanguageCacheIdPart example

  protected function getRouteCollectionCacheId(Request $request) {
    // Include the current language code in the cache identifier as     // the language information can be elsewhere than in the path, for example     // based on the domain.     $this->addExtraCacheKeyPart('language', $this->getCurrentLanguageCacheIdPart());

    // Sort the cache key parts by their provider in order to have predictable     // cache keys.     ksort($this->extraCacheKeyParts);
    $key_parts = [];
    foreach ($this->extraCacheKeyParts as $provider => $key_part) {
      $key_parts[] = '[' . $provider . ']=' . $key_part;
    }

    return 'route:' . implode(':', $key_parts) . ':' . $request->getPathInfo() . ':' . $request->getQueryString();
  }