func (us *unsafeSet) ContainsAll(values []string) bool {
	for _, s := range values {
		if !us.Contains(s) {
			return false
		}
	}
	return true
}
func (us *unsafeSet) ContainsAll(values []string) bool {
	for _, s := range values {
		if !us.Contains(s) {
			return false
		}
	}
	return true
}
// ContainsAll returns whether the set contains all given values