func (s Set) Remove(label string) {
	delete(s.members, label)
}
Remove removes a member from the set
package set
type Set struct {
	members map[string]bool
}
func New(names []string) Set {
	result := make(map[string]bool, len(names))
	for _, n := range names {
		result[n] = true
	}
	return Set{result}
}
func (s Set) Add(label string) {
	s.members[label] = true
}
func (s Set) Has(label string) bool {
	_, ok := s.members[label]
	return ok
}