code: func GenerateSecretKey() []byte {
  	secretData := make([]byte, naclSecretboxKeySize)
  	if _, err := io.ReadFull(cryptorand.Reader, secretData); err != nil {
  		// panic if we can't read random data
  		panic(errors.Wrap(err, "failed to read random bytes"))
  	}
  	return secretData
  }
docs: // GenerateSecretKey generates a secret key that can be used for encrypting data
  // using this package