public function getWeight(array $order, array &$cart)
    {
        $result = null;
        $this->hook->attach('order.weight.get.before', $order, $cart, $result, $this);

        if (isset($result)) {
            return (float) $result;
        }

        $total = 0.0;
        foreach ($cart['items'] as &$item) {
            $this->sumTotalWeight($total, $item, $order);
        }

        $result = round($total, 2);
        $this->hook->attach('order.weight.get.after', $order, $cart, $result, $this);
        return (float) $result;
    }