docs: def active_url(context, urls, css=None):
      """
      Highlight menu item based on url tag.
      
      Returns a css class if ``request.path`` is in given ``url``.
      
      :param url:
          Django url to be reversed.
  
      :param css:
          Css class to be returned for highlighting. Return active if none set.
  
      """
      request = context['request']
      if request.get_full_path in (reverse(url) for url in urls.split()):
          return css if css else 'active'
      return ''