public function testExpire() {
$response = new Response();
$response->headers
->set('Cache-Control', 'max-age=100');
$response
->expire();
$this
->assertEquals(100, $response->headers
->get('Age'), '->expire() sets the Age to max-age when present');
$response = new Response();
$response->headers
->set('Cache-Control', 'max-age=100, s-maxage=500');
$response
->expire();
$this
->assertEquals(500, $response->headers
->get('Age'), '->expire() sets the Age to s-maxage when both max-age and s-maxage are present');
$response = new Response();
$response->headers
->set('Cache-Control', 'max-age=5, s-maxage=500');
$response->headers
->set('Age', '1000');
$response
->expire();
$this
->assertEquals(1000, $response->headers
->get('Age'), '->expire() does nothing when the response is already stale/expired');
$response = new Response();
$response
->expire();
$this
->assertFalse($response->headers
->has('Age'), '->expire() does nothing when the response does not include freshness information');
}