public function testExpiresAfter()
{
$item = new CacheItem('test_key');
$this->assertNull($item->getExpirationDate());
$item->expiresAfter(null);
$this->assertNull($this->getExpectedException());
$item->expiresAfter(new \DateInterval('PT1S'));
$this->assertEquals(new \DateTime('+1 second'), $item->getExpirationDate());
$item->expiresAfter(1);
$this->assertEquals(new \DateTime('+1 second'), $item->getExpirationDate());
}
