hasVary example

    else {
      $timestamp = $response->getLastModified()->getTimestamp();
    }
    $response->setEtag($timestamp);

    // Allow HTTP proxies to cache pages for anonymous users without a session     // cookie. The Vary header is used to indicates the set of request-header     // fields that fully determines whether a cache is permitted to use the     // response to reply to a subsequent request for a given URL without     // revalidation.     if (!$response->hasVary() && !Settings::get('omit_vary_cookie')) {
      $response->setVary('Cookie', FALSE);
    }
  }

  /** * Disable caching in the browser and for HTTP/1.1 proxies and clients. * * @param \Symfony\Component\HttpFoundation\Response $response * A response object. */
  protected function setCacheControlNoCache(Response $response) {
    

$this->assertFalse($this->response->headers->hasCacheControlDirective('public'));
        $this->assertTrue($this->response->headers->hasCacheControlDirective('private'));
    }

    public function testResponseVary()
    {
        $vary = ['foobar'];
        $request = $this->createRequest(new Cache(vary: $vary));

        $this->listener->onKernelResponse($this->createEventMock($request, $this->response));
        $this->assertTrue($this->response->hasVary());
        $result = $this->response->getVary();
        $this->assertSame($vary, $result);
    }

    public function testResponseVaryWhenVaryNotSet()
    {
        $request = $this->createRequest(new Cache());
        $vary = ['foobar'];
        $this->response->setVary($vary);

        $this->listener->onKernelResponse($this->createEventMock($request, $this->response));
        

$this->assertTrue($response->isClientError());
        $this->assertFalse($response->isServerError());

        $response = new Response('', 500);
        $this->assertFalse($response->isClientError());
        $this->assertTrue($response->isServerError());
    }

    public function testHasVary()
    {
        $response = new Response();
        $this->assertFalse($response->hasVary());

        $response->setVary('User-Agent');
        $this->assertTrue($response->hasVary());
    }

    public function testSetEtag()
    {
        $response = new Response('', 200, ['ETag' => '"12345"']);
        $response->setEtag(null);

        $this->assertNull($response->headers->get('Etag'), '->setEtag() removes Etags when call with null');
    }