code: func (s *Session) Put(item mo.Reference) mo.Reference {
  	ref := item.Reference()
  	if ref.Value == "" {
  		ref.Value = fmt.Sprintf("session[%s]%s", s.Key, uuid.New())
  	}
  	s.Registry.setReference(item, ref)
  	return s.Registry.Put(item)
  }
docs: // Put wraps Registry.Put, setting the moref value to include the session key.