code: func (s *ProxyStore) Instances(service string) ([]*discoverd.Instance, error) {
  	host := s.Peers[rand.Intn(len(s.Peers))]
  	client := discoverd.NewClientWithURL("http://" + host)
  	return client.Service(service).Instances()
  }
docs: // Instances returns a list of instances for a service.