code: func (t *stiTar) CreateTarFile(base, dir string) (string, error) {
  	tarFile, err := ioutil.TempFile(base, "tar")
  	defer tarFile.Close()
  	if err != nil {
  		return "", err
  	}
  	if err = t.CreateTarStream(dir, false, tarFile); err != nil {
  		return "", err
  	}
  	return tarFile.Name(), nil
  }
docs: // CreateTarFile creates a tar file from the given directory
  // while excluding files that match the given exclusion pattern
  // It returns the name of the created file