oldestProtocol := oldestService.Ports[0].Protocol
		if oldestProtocol != protocol.HTTP && isHTTPListener(listeners[0]) {
			t.Fatal("expected TCP listener, found HTTP")
		} else if oldestProtocol == protocol.HTTP && !isHTTPListener(listeners[0]) {
			t.Fatal("expected HTTP listener, found TCP")
		}

		// Validate that listener conflict preserves the listener of oldest service.

	if got == nil {
		return nil
	}
	s, err := protomarshal.Marshal(got)
	if err != nil {
		t.Fatal(err)
	}
	meta := clusterServicesMetadata{}
	if err := json.Unmarshal(s, &meta); err != nil {
		t.Fatal(err)
	}
	res := []string{}
	for _, m := range meta.Services {
		res = append(res, m.Host)
	}
	return res
}