code: func HomeDir() string {
  	failInTests()
  	if runtime.GOOS == "windows" {
  		return os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
  	}
  	return os.Getenv("HOME")
  }
docs: // HomeDir returns the path to the user's home directory.
  // It returns the empty string if the value isn't known.