buildPositions example

ShippingMethodEntity $shippingMethod,
        LineItemCollection $collection,
        SalesChannelContext $context
    ): ?Delivery {
        $positions = new DeliveryPositionCollection();
        $deliveryTime = null;
        // use shipping method delivery time as default         if ($shippingMethod->getDeliveryTime() !== null) {
            $deliveryTime = DeliveryTime::createFromEntity($shippingMethod->getDeliveryTime());
        }

        $this->buildPositions($collection, $positions, $deliveryTime);

        if ($positions->count() <= 0) {
            return null;
        }

        return new Delivery(
            $positions,
            $this->getDeliveryDateByPositions($positions),
            $shippingMethod,
            $context->getShippingLocation(),
            new CalculatedPrice(0, 0, new CalculatedTaxCollection(), new TaxRuleCollection())
        );