public function output(UnitTester $I)
{
$I->wantTo('Cache output fragments by using Redis as cache backend');
$time = date('H:i:s');
$cache = new Redis(new Output(['lifetime' => 2]), ['host' => TEST_RS_HOST, 'port' => TEST_RS_PORT]);
ob_start();
// First time cache
$content = $cache->start('test-output');
$I->assertNull($content);
echo $time;
$cache->save(null, null, null, true);
$obContent = ob_get_contents();
ob_end_clean();
$I->assertEquals($time, $obContent);
$I->seeInRedis('_PHCR' . 'test-output', $time);
// Expect same cache
$content = $cache->start('test-output');
$I->assertNotNull($content);
$I->assertEquals($time, $obContent);
$I->seeInRedis('_PHCR' . 'test-output', $time);
sleep(2);
$content = $cache->start('test-output');
$I->assertNull($content);
$I->dontSeeInRedis('_PHCR' . 'test-output');
}