src/Service/ResponseConfigurator.php
protected function setLastModified(Response $response, \DateTime $last_modified)
    {
        $response
            ->setLastModified($last_modified)
            ->headers
            ->addCacheControlDirective('must-revalidate', true);

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

        return $this;
    }
@param Response $response
@param \DateTime $last_modified

@return ResponseConfigurator