sendEarlyHints example

$this->assertContains($link2, $links);
    }

    public function testSendEarlyHints()
    {
        $container = new Container();
        $container->set('web_link.http_header_serializer', new HttpHeaderSerializer());

        $controller = $this->createController();
        $controller->setContainer($container);

        $response = $controller->sendEarlyHints([
            (new Link(href: '/style.css'))->withAttribute('as', 'stylesheet'),
            (new Link(href: '/script.js'))->withAttribute('as', 'script'),
        ]);

        $this->assertSame('</style.css>; rel="preload"; as="stylesheet",</script.js>; rel="preload"; as="script"', $response->headers->get('Link'));
    }
}