util.go
func newSeed() int64 {
	r, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
	if err != nil {
		panic(fmt.Errorf("failed to read random bytes: %v", err))
	}
	return r.Int64()
}
func newSeed() int64 {
	r, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
	if err != nil {
		panic(fmt.Errorf("failed to read random bytes: %v", err))
	}
	return r.Int64()
}
// returns an int64 from a crypto random source
// can be used to seed a source for a math/rand.