public function testGetLifetime() {
$bag = new MetadataBag();
$array = array(
MetadataBag::CREATED => 1234567,
MetadataBag::UPDATED => 12345678,
MetadataBag::LIFETIME => 1000,
);
$bag
->initialize($array);
$this
->assertEquals(1000, $bag
->getLifetime());
}