code: func MkdirAndChown(path string, mode os.FileMode, owner Identity) error {
  	return mkdirAs(path, mode, owner, false, true)
  }
docs: // MkdirAndChown creates a directory and then modifies ownership to the requested uid/gid.
  // If the directory already exists, this function still changes ownership.
  // Note that unlike os.Mkdir(), this function does not return IsExist error
  // in case path already exists.