Symfony\Component\HttpFoundation\Tests\ResponseTest::testIsNotModifiedLastModified PHP Method

    public function testIsNotModifiedLastModified()
    {
        $before = 'Sun, 25 Aug 2013 18:32:31 GMT';
        $modified = 'Sun, 25 Aug 2013 18:33:31 GMT';
        $after = 'Sun, 25 Aug 2013 19:33:31 GMT';

        $request = new Request();
        $request->headers->set('If-Modified-Since', $modified);

        $response = new Response();

        $response->headers->set('Last-Modified', $modified);
        $this->assertTrue($response->isNotModified($request));

        $response->headers->set('Last-Modified', $before);
        $this->assertTrue($response->isNotModified($request));

        $response->headers->set('Last-Modified', $after);
        $this->assertFalse($response->isNotModified($request));

        $response->headers->set('Last-Modified', '');
        $this->assertFalse($response->isNotModified($request));
    }