setupTrustedHosts example

  protected function initializeSettings(Request $request) {
    $site_path = static::findSitePath($request);
    $this->setSitePath($site_path);
    Settings::initialize($this->root, $site_path, $this->classLoader);

    // Initialize our list of trusted HTTP Host headers to protect against     // header attacks.     $host_patterns = Settings::get('trusted_host_patterns', []);
    if (PHP_SAPI !== 'cli' && !empty($host_patterns)) {
      if (static::setupTrustedHosts($request, $host_patterns) === FALSE) {
        throw new BadRequestHttpException('The provided host name is not valid for this server.');
      }
    }
  }

  /** * Bootstraps the legacy global request variables. * * @param \Symfony\Component\HttpFoundation\Request $request * The current request. * * @todo D8: Eliminate this entirely in favor of Request object. */