Doing a redirect in Drupal 8

https://api.drupal.org/api/drupal/vendor!symfony!http-foundation!RedirectResponse.php/class/RedirectResponse/8.6.x

It appears we can simply pass in the URL and the status code!

https://api.drupal.org/api/drupal/vendor%21symfony%21http-foundation%21RedirectResponse.php/function/RedirectResponse%3A%3A__construct/8.6.x

Super simple:

use Drupal\Core\Controller\ControllerBase;

\\ ... inside some method eventually

    return new RedirectResponse($new_path, $new_status);