public function testFetchesResponseFromBackendWhenCacheMisses() {
$time = \DateTime::createFromFormat('U', time() + 5);
$this
->setNextResponse(200, array(
'Cache-Control' => 'public',
'Expires' => $time
->format(DATE_RFC2822),
));
$this
->request('GET', '/');
$this
->assertEquals(200, $this->response
->getStatusCode());
$this
->assertTraceContains('miss');
$this
->assertTrue($this->response->headers
->has('Age'));
}