code: func HandleSwarmingLog(c *router.Context) error {
  	log, closed, err := swarming.GetLog(
  		c.Context,
  		c.Request.FormValue("server"),
  		c.Params.ByName("id"),
  		c.Params.ByName("logname"))
  	if err != nil {
  		return err
  	}
  
  	templates.MustRender(c.Context, c.Writer, "pages/log.html", templates.Args{
  		"Log":    log,
  		"Closed": closed,
  	})
  	return nil
  }
docs: // HandleSwarmingLog renders a step log from a swarming build.