code: def mark_as_read(self, request, pk):
          
          if self.top_level_forum is not None:
              forums = request.forum_permission_handler.get_readable_forums(
                  self.top_level_forum.get_descendants(include_self=True), request.user,
              )
          else:
              forums = request.forum_permission_handler.get_readable_forums(
                  Forum.objects.all(), request.user,
              )
  
          # Marks forums as read
          track_handler.mark_forums_read(forums, request.user)
  
          if len(forums):
              messages.success(request, self.success_message)
  
          return HttpResponseRedirect(self.get_top_level_forum_url())
docs: Marks the considered forums as read.