func BTCAddrBytesFromPubKeyBytes(pubKeyBytes []byte) (addrBytes []byte, checksum []byte) {
	versionPrefix := btcPrefixPubKeyHash // TODO Make const or configurable
	h160 := CalcHash160(pubKeyBytes)
	_h160 := append([]byte{versionPrefix}, h160...)
	checksum = CalcHash256(_h160)[:4]
	return h160, checksum
}
func BTCAddrBytesFromPubKeyBytes(pubKeyBytes []byte) (addrBytes []byte, checksum []byte) {
	versionPrefix := btcPrefixPubKeyHash // TODO Make const or configurable
	h160 := CalcHash160(pubKeyBytes)
	_h160 := append([]byte{versionPrefix}, h160...)
	checksum = CalcHash256(_h160)[:4]
	return h160, checksum
}
// BTCAddrBytesFromPubKeyBytes returns a hex Bitcoin mainnet address and its checksum.