code: func GetVersionFromTarsum(tarsum string) (Version, error) {
  	tsv := tarsum
  	if strings.Contains(tarsum, "+") {
  		tsv = strings.SplitN(tarsum, "+", 2)[0]
  	}
  	for v, s := range tarSumVersions {
  		if s == tsv {
  			return v, nil
  		}
  	}
  	return -1, ErrNotVersion
  }
docs: // GetVersionFromTarsum returns the Version from the provided string.