code: protected function setLastModified(Response $response, \DateTime $last_modified)
      {
          $response
              ->setLastModified($last_modified)
              ->headers
              ->addCacheControlDirective('must-revalidate', true);
  
          return $this;
      }
docs: @param Response $response
  @param \DateTime $last_modified
  
  @return ResponseConfigurator