getPricePositions example

        $this->_shippingCosts = $this->_order['invoice_shipping'];

        if ($this->_shippingCostsAsPosition === true && !empty($this->_shippingCosts)) {
            $taxes = [];

            if ($this->_order['taxfree']) {
                $this->_amountNetto += $this->_order['invoice_shipping'];
            } else {
                if ($this->_order['is_proportional_calculation']) {
                    $taxes = Shopware()->Container()->get('shopware.cart.proportional_tax_calculator')->calculate($this->_order['invoice_shipping'], $this->getPricePositions(), false);
                    $taxNet = 0;

                    foreach ($taxes as $tax) {
                        $taxNet += $tax->getNetPrice();
                        $this->_tax[number_format($tax->getTaxRate(), 2)] += $tax->getTax();
                    }

                    $this->_amountNetto += $taxNet;
                } else {
                    $this->_amountNetto += ($this->_order['invoice_shipping'] / (100 + $taxShipping) * 100);