code: func untarHandler(tarArchive io.Reader, dest string, options *TarOptions, decompress bool) error {
  	if tarArchive == nil {
  		return fmt.Errorf("Empty archive")
  	}
  	dest = filepath.Clean(dest)
  	if options == nil {
  		options = &TarOptions{}
  	}
  	if options.ExcludePatterns == nil {
  		options.ExcludePatterns = []string{}
  	}
  
  	r := tarArchive
  	if decompress {
  		decompressedArchive, err := DecompressStream(tarArchive)
  		if err != nil {
  			return err
  		}
  		defer decompressedArchive.Close()
  		r = decompressedArchive
  	}
  
  	return Unpack(r, dest, options)
  }
docs: // Handler for teasing out the automatic decompression