code: func EasyOpen(box []byte, key nacl.Key) ([]byte, error) {
  	if len(box) < 24 {
  		return nil, errors.New("secretbox: message too short")
  	}
  	decryptNonce := new([24]byte)
  	copy(decryptNonce[:], box[:24])
  	decrypted, ok := Open([]byte{}, box[24:], decryptNonce, key)
  	if !ok {
  		return nil, errInvalidInput
  	}
  	return decrypted, nil
  }
docs: // EasyOpen decrypts box using key. We assume a 24-byte nonce is prepended to
  // the encrypted text in box. The key and nonce pair must be unique for each
  // distinct message.