code: func (s *Service) FireAllTasksHandler(c *router.Context) {
  	if err := s.FireAllTasks(c.Context); err != nil {
  		c.Writer.WriteHeader(http.StatusInternalServerError)
  		fmt.Fprintf(c.Writer, "fire_all_tasks failed: %s", err)
  	} else {
  		c.Writer.Write([]byte("ok"))
  	}
  }
docs: // FireAllTasksHandler is an HTTP handler that expects `logging` and `luci/gae`
  // services to be installed into the context.
  //
  // FireAllTasksHandler verifies that it was called within an Appengine Cron
  // request, and then invokes the FireAllTasks function.