public function testPrevNextItem()
{
$package = new Package();
$first = new Item($package, new LocalImage('first'));
$this->assertNull($package->getPrev($first));
$this->assertNull($package->getNext($first));
$second = new Item($package, new LocalImage('second'));
$this->assertEquals($first, $package->getPrev($second));
$this->assertEquals($second, $package->getNext($first));
}