public function setUp()
{
$this->operation = new CacheLifetimeOperation();
$this->now = new \DateTime();
$this->inject($this->operation, 'now', $this->now);
$inOneDay = clone $this->now;
$inOneDay->add(new \DateInterval('P1D'));
$inTwoDays = clone $this->now;
$inTwoDays->add(new \DateInterval('P2D'));
$oneDayAgo = clone $this->now;
$oneDayAgo->sub(new \DateInterval('P1D'));
$this->dateFixtures = array('now' => $this->now, '+1D' => $inOneDay, '+2D' => $inTwoDays, '-1D' => $oneDayAgo);
}