code: func (msg *ReceivedMessage) decryptAsymmetric(key *ecdsa.PrivateKey) error {
  	decrypted, err := ecies.ImportECDSA(key).Decrypt(msg.Raw, nil, nil)
  	if err == nil {
  		msg.Raw = decrypted
  	}
  	return err
  }
docs: // decryptAsymmetric decrypts an encrypted payload with a private key.