code: func HandlerBuilder(i interface{}) (scaffold.Handler, error) {
  	switch i.(type) {
  	case Handler:
  		return build(i.(Handler)), nil
  	case func(context.Context, http.ResponseWriter, *http.Request) error:
  		return build(HandlerFunc(i.(func(context.Context, http.ResponseWriter, *http.Request) error))), nil
  	}
  
  	return nil, errors.New("Invalid type")
  }
docs: // HandlerBuilder can be used to create a scaffold.Handler based on a Handler