code: func TouchDirAll(dir string) error {
  	err := os.MkdirAll(dir, privateDirMode)
  	if err != nil && err != os.ErrExist {
  		return err
  	}
  	return IsDirWriteable(dir)
  }
docs: // TouchDirAll is similar to os.MkdirAll. It creates directories with 0700 permission if any directory
  // does not exists. TouchDirAll also ensures the given directory is writable.