func (d *digest) Sum(in []byte) []byte {
	s := d.Sum64()
	in = append(in, byte(s))
	in = append(in, byte(s>>8))
	in = append(in, byte(s>>16))
	in = append(in, byte(s>>24))
	in = append(in, byte(s>>32))
	in = append(in, byte(s>>40))
	in = append(in, byte(s>>48))
	in = append(in, byte(s>>56))
	return in
}
func (d *digest) Sum(in []byte) []byte {
	s := d.Sum64()
	in = append(in, byte(s))
	in = append(in, byte(s>>8))
	in = append(in, byte(s>>16))
	in = append(in, byte(s>>24))
	in = append(in, byte(s>>32))
	in = append(in, byte(s>>40))
	in = append(in, byte(s>>48))
	in = append(in, byte(s>>56))
	return in
}
func ( d * digest ) Sum ( in [ ] byte ) [ ] byte { s := d . Sum64 ( ) in = append ( in , byte ( s ) ) in = append ( in , byte ( s >> 8 ) ) in = append ( in , byte ( s >> 16 ) ) in = append ( in , byte ( s >> 24 ) ) in = append ( in , byte ( s >> 32 ) ) in = append ( in , byte ( s >> 40 ) ) in = append ( in , byte ( s >> 48 ) ) in = append ( in , byte ( s >> 56 ) ) return in }
// Encode in little endian
Encode in little endian