data/misc.go
func Uint192ToBytes(x *big.Int) [24]byte {
	var ret [24]byte
	xBytes := x.Bytes()
	for i, v := range xBytes {
		ret[24-len(xBytes)+i] = v
	}
	return ret
}
func Uint192ToBytes(x *big.Int) [24]byte {
	var ret [24]byte
	xBytes := x.Bytes()
	for i, v := range xBytes {
		ret[24-len(xBytes)+i] = v
	}
	return ret
}
// Uint192ToBytes using big endian with leading zeros.