code: func packTo(srcPath, destPath string, fn cae.HookFunc, includeDir bool) error {
  	fw, err := os.Create(destPath)
  	if err != nil {
  		return err
  	}
  	defer fw.Close()
  
  	return packToWriter(srcPath, fw, fn, includeDir)
  }
docs: // packTo packs given source path object to target path.