extSvcSelector := buildServiceWithPort("example2.com", 9999, protocol.TCP, tnow)
	extSvcSelector.Resolution = model.Passthrough
	extSvcSelector.Attributes.ServiceRegistry = provider.External
	extSvcSelector.Attributes.LabelSelectors = map[string]string{"foo": "bar"}

	tests := []struct {
		name                      string
		instances                 []*model.ServiceInstance
		services                  []*model.Service