code: func (u *DockerRegistryURL) Path() string {
  	if u.Tag == "" {
  		return u.ImageName
  	} else {
  		return fmt.Sprintf("%s:%s", u.ImageName, u.Tag)
  	}
  }
docs: // Path returns the string path segment of a DockerRegistryURL. The full format
  // of a path is [namespace/]repo[:tag].