public function testContains()
{
$session = $this->getMockBuilder('PHPCR\\SessionInterface')->getMock();
$dm = DocumentManager::create($session);
$obj = new \stdClass();
$uow = $dm->getUnitOfWork();
$method = new \ReflectionMethod($uow, 'registerDocument');
$method->setAccessible(true);
$method->invoke($uow, $obj, '/foo');
$method->setAccessible(false);
$this->assertTrue($dm->contains($obj));
}