code: func (fs *FileAddrStorage) SetAddresses(addrs []NetAddr) error {
  	bytes, err := json.Marshal(addrs)
  	if err != nil {
  		return trace.Wrap(err)
  	}
  	err = ioutil.WriteFile(fs.filePath, bytes, 0666)
  	if err != nil {
  		log.Error(err)
  		return trace.ConvertSystemError(err)
  	}
  	return nil
  }
docs: // SetAddresses updates storage with new address list