code: func (p *PublicKey) SerializeHybrid() []byte {
  	b := make([]byte, 0, PubKeyBytesLenHybrid)
  	format := pubkeyHybrid
  	if isOdd(p.Y) {
  		format |= 0x1
  	}
  	b = append(b, format)
  	b = paddedAppend(32, b, p.X.Bytes())
  	return paddedAppend(32, b, p.Y.Bytes())
  }
docs: // SerializeHybrid serializes a public key in a 65-byte hybrid format.