public function testCheckedAt()
{
$job = new Job('a');
$this->assertNull($job->getCheckedAt());
$job->checked();
$this->assertInstanceOf('DateTime', $checkedAtA = $job->getCheckedAt());
$job->checked();
$this->assertInstanceOf('DateTime', $checkedAtB = $job->getCheckedAt());
$this->assertNotSame($checkedAtA, $checkedAtB);
}
