removeLineItemsExtension example

private function resetDataTimestamps(LineItemCollection $items): void
    {
        foreach ($items as $item) {
            $item->setDataTimestamp(null);
            $item->setDataContextHash(null);
            $this->resetDataTimestamps($item->getChildren());
        }
    }

    private function removeExtensions(Cart $cart): void
    {
        $this->removeLineItemsExtension($cart->getLineItems());

        foreach ($cart->getDeliveries() as $delivery) {
            $delivery->setExtensions([]);

            $delivery->getShippingMethod()->setExtensions([]);

            foreach ($delivery->getPositions() as $position) {
                $position->setExtensions([]);
                $this->removeLineItemsExtension(new LineItemCollection([$position->getLineItem()]));
            }
        }