code: func (e *ClientExecutor) CreateScratchImage() (string, error) {
  	random, err := randSeq(imageSafeCharacters, 24)
  	if err != nil {
  		return "", err
  	}
  	name := fmt.Sprintf("scratch%s", random)
  
  	buf := &bytes.Buffer{}
  	w := tar.NewWriter(buf)
  	w.Close()
  
  	return name, e.Client.ImportImage(docker.ImportImageOptions{
  		Repository:  name,
  		Source:      "-",
  		InputStream: buf,
  	})
  }
docs: // CreateScratchImage creates a new, zero byte layer that is identical to "scratch"
  // except that the resulting image will have two layers.