buildFeatures example

        foreach ($lineItems as $lineItem) {
            $product = $data->get(
                $this->getDataKey($lineItem->getReferencedId())
            );

            if (!($product instanceof SalesChannelProductEntity)) {
                continue;
            }

            $lineItem->replacePayload([
                'features' => $this->buildFeatures($data, $lineItem, $product),
            ]);
        }
    }

    private function buildFeatures(CartDataCollection $data, LineItem $lineItem, SalesChannelProductEntity $product): array
    {
        $features = [];
        $featureSet = $product->getFeatureSet();

        if ($featureSet === null) {
            return $features;
        }