private function addRecommendedProducts(
        &$productsToDisplayCounter,
        $limit,
        $maxPerChild,
        $recommendedProducts,
        &$productsToDisplay,
        &$product
    ) {
        $i = 0;

        foreach ($recommendedProducts as $product) {
            //check if still exists
            if ($product->getId() && $productsToDisplayCounter < $limit
                && $i <= $maxPerChild
                && $product->isSaleable()
                && !$product->getParentId()
            ) {
                //we have a product to display
                $productsToDisplay[$product->getId()] = $product;
                $i++;
                $productsToDisplayCounter++;
            }
        }
    }