code: func txHexString(tx *wire.MsgTx) string {
  	buf := bytes.NewBuffer(make([]byte, 0, tx.SerializeSize()))
  	// Ignore Serialize's error, as writing to a bytes.buffer cannot fail.
  	tx.Serialize(buf)
  	return hex.EncodeToString(buf.Bytes())
  }
docs: // txHexString returns the serialized transaction encoded in hexadecimal.