Merging line items with the same SKU for bundles in Shopify order packing slips

packing_slip.liquid

{% assign unique_line_item_skus = line_items_in_shipment | map: 'sku' | uniq %}
{% for line_item_sku in unique_line_item_skus %}
  {% assign total_quantity = 0 %}
  {% assign total_shipping_quantity = 0 %}

  {% assign sku_line_items = line_items_in_shipment | where: "sku", line_item_sku %}
  {% for line_item in sku_line_items %}
    {% assign total_quantity = total_quantity | plus: line_item.quantity %}
    {% assign total_shipping_quantity = total_shipping_quantity | plus: line_item.shipping_quantity %}
  {% endfor %}
  {% assign line_item = sku_line_items | first %}
  
  <!-- Keep the existing template intact in the for loop intact --> 

{% endfor %}