Method getTotal

public function getTotal()
{
    $items = array('netto', 'brutto', 'quantity', 'weight', 'length', 'width', 'height');
    foreach ($items as $k => $v) {
        if (!isset($this->total[0][$v])) {
            $this->total[0][$v] = 0;
        }
    }
    return $this->total;
}