 {%- assign string_ordered_pages = string_ordered_pages | concat: group.items -%}
    {%- else -%}
      {%- assign number_ordered_pages = number_ordered_pages | concat: group.items -%}
    {%- endif -%}
  {%- endfor -%}
  
  {%- assign sorted_number_ordered_pages = number_ordered_pages | sort:"nav_order" -%}
  
  {%- comment -%}
    The string_ordered_pages have to be sorted by nav_order, and otherwise title
    (where appending the empty string to a numeric title converts it to a string).
    After groupi