code: func SetNamespace(namespace string) VisitorFunc {
  	return func(info *Info, err error) error {
  		if err != nil {
  			return err
  		}
  		if !info.Namespaced() {
  			return nil
  		}
  		if len(info.Namespace) == 0 {
  			info.Namespace = namespace
  			UpdateObjectNamespace(info, nil)
  		}
  		return nil
  	}
  }
docs: // SetNamespace ensures that every Info object visited will have a namespace
  // set. If info.Object is set, it will be mutated as well.