code: func Encode(image Image) string {
  	repo := image.Repository
  	if image.Registry != "" {
  		repo = fmt.Sprintf("%s/%s", image.Registry, repo)
  	}
  
  	if image.Digest != "" {
  		return fmt.Sprintf("%s@%s", repo, image.Digest)
  	} else if image.Tag != "" {
  		return fmt.Sprintf("%s:%s", repo, image.Tag)
  	}
  
  	return repo
  }
docs: // Encode encodes an Image to it's string representation.