code: def add_entries_to_gallery(app, doctree, docname):
      
      if docname != 'gallery':
          return
  
      if not has_gallery(app.builder.name):
          return
  
      # Find gallery node
      try:
          node = doctree.traverse(gallery)[0]
      except TypeError:
          return
  
      content = []
      for entry in app.env.gallery_entries:
          raw_html_node = nodes.raw('', text=entry.html, format='html')
          content.append(raw_html_node)
  
      # Even when content is empty, we want the gallery node replaced
      node.replace_self(content)
docs: Add entries to the gallery node
  
      Should happen when all the doctrees have been read
      and the gallery entries have been collected. i.e at
      doctree-resolved time.