code: func BuilderHandler(c *router.Context, builderID buildsource.BuilderID) error {
  	limit := 25
  	if tLimit := GetLimit(c.Request, -1); tLimit >= 0 {
  		limit = tLimit
  	}
  	builder, err := builderID.Get(c.Context, limit, c.Request.FormValue("cursor"))
  	if err != nil {
  		return err
  	}
  	templates.MustRender(c.Context, c.Writer, "pages/builder.html", templates.Args{
  		"Builder": builder,
  	})
  	return nil
  }
docs: // BuilderHandler is responsible for taking a universal builder ID and rendering
  // the builder page (defined in ./appengine/templates/pages/builder.html).
  // We don't need to do an ACL check because this endpoint delegates all ACL checks
  // authentication to Buildbucket with the RPC calls.