func (s *Bits) UnsetAll() {
	*s = 0
}
UnsetAll set all bits to 0
package bitset
type Bits uint64
func NewBits() *Bits {
	var s Bits
	return &s
}
func BitsList(bits ...uint) *Bits {
	var s uint64
	for _, b := range bits {
		s |= uint64(1 << b)
	}
	return ((*Bits)(&s))
}
func BitsFrom(b uint) *Bits {
	var s Bits = Bits(b)
	return &s
}
func (s *Bits) Set(index uint) {
	*s |= 1 << index
}
func (s *Bits) SetAll() {
	*s = 1<<64 - 1
}
func (s *Bits) Unset(index uint) {
	*s &= ^(1 << index)
}