function testWeightVariance()
{
$box = new TestBox('Box', 10, 10, 10, 10, 10, 10, 10, 10);
$item = new TestItem('Item', 5, 10, 10, 10, true);
$boxItems = new ItemList();
$boxItems->insert($item);
$packedBox = new PackedBox($box, $boxItems, 1, 2, 3, 4);
$packedBoxList = new PackedBoxList();
$packedBoxList->insert($packedBox);
self::assertEquals(0, $packedBoxList->getWeightVariance());
}