docs: def render_robots_meta_tag(context):
      """
      Returns the robots meta tag.
      """
      request = context['request']
      robots_indexing = None
      robots_following = None
  
      # Prevent indexing any unwanted domains (e.g. staging).
      if context.request.get_host() in settings.META_TAGGER_ROBOTS_DOMAIN_WHITELIST:
  
          # Try to get the title from the context object (e.g. DetailViews).
          if context.get('object'):
              try:
                  robots_indexing = context['object'].get_robots_indexing()
                  robots_following = context['object'].get_robots_following()
              except AttributeError:
                  pass
          elif context.get('meta_tagger'):
              robots_indexing = context['meta_tagger'].get('robots_indexing', robots_indexing)
              robots_following = context['meta_tagger'].get('robots_following', robots_following)
  
          # Try fetching the robots values of the cms page.
          if robots_indexing is None:
              try:
                  robots_indexing = request.current_page.metatagpageextension.robots_indexing
              except (AttributeError, NoReverseMatch, MetaTagPageExtension.DoesNotExist):
                  robots_indexing = True
  
          if robots_following is None:
              try:
                  robots_following = request.current_page.metatagpageextension.robots_following
              except (AttributeError, NoReverseMatch, MetaTagPageExtension.DoesNotExist):
                  robots_following = True
  
      return mark_safe('<meta name="robots" content="{robots_indexing}, {robots_following}">'.format(
          robots_indexing='index' if robots_indexing else 'noindex',
          robots_following='follow' if robots_following else 'nofollow'
      ))