nil"  -%}

  {%- comment -%}
    The nav_ordered_pages have to be added to number_ordered_pages and
    string_ordered_pages, depending on the nav_order value.
    The first character of the jsonify result is `"` only for strings.
  {%- endcomment -%}
  {%- assign nav_ordered_groups = nav_ordered_pages
        | group_by_exp:"item", "item.nav_order | jsonify | slice: 0" -%}
  {%- assign number_ordered_pages = "" | split:"X" -%}
  {%- for group in nav_ordered_groups -%}
    {%- if group.name == '"' -%}
     