code: func Write(kiteKey string) error {
  	keyPath, err := kiteKeyPath()
  	if err != nil {
  		return err
  	}
  
  	err = os.MkdirAll(filepath.Dir(keyPath), 0700)
  	if err != nil {
  		return err
  	}
  
  	// Need to remove the previous key first because we can't write over
  	// when previous file's mode is 0400.
  	os.Remove(keyPath)
  
  	return ioutil.WriteFile(keyPath, []byte(kiteKey), 0400)
  }
docs: // Write over the kite.key file.