code: func parseRepositoryTag(repos string) (string, string) {
  	n := strings.Index(repos, "@")
  	if n >= 0 {
  		parts := strings.Split(repos, "@")
  		return parts[0], parts[1]
  	}
  	n = strings.LastIndex(repos, ":")
  	if n < 0 {
  		return repos, ""
  	}
  	if tag := repos[n+1:]; !strings.Contains(tag, "/") {
  		return repos[:n], tag
  	}
  	return repos, ""
  }
docs: // Copied from https://github.com/docker/docker/blob/50a1d0f0ef83a9ed55ea2caaa79539ec835877a3/pkg/parsers/parsers.go#L71-L89