func Copy(current []*registry.Service) []*registry.Service
Copy makes a copy of services
func CopyService(service *registry.Service) *registry.Service
CopyService make a copy of service
func Merge(olist []*registry.Service, nlist []*registry.Service) []*registry.Service
Merge merges two lists of services and returns a new copy
func Remove(old, del []*registry.Service) []*registry.Service
Remove removes services and returns a new copy