appServer := grpc.NewServer()
	healthServer := health.NewServer()
	healthServer.SetServingStatus("serving-svc", grpcHealth.HealthCheckResponse_SERVING)
	healthServer.SetServingStatus("unknown-svc", grpcHealth.HealthCheckResponse_UNKNOWN)
	healthServer.SetServingStatus("not-serving-svc", grpcHealth.HealthCheckResponse_NOT_SERVING)
	grpcHealth.RegisterHealthServer(appServer, healthServer)

	listener, err := net.Listen("tcp", ":0")
	if err != nil {

		return
	}
	defer conn.Close()

	var svc string
	if prober.GRPC.Service != nil {
		svc = *prober.GRPC.Service
	}
	grpcClient := grpcHealth.NewHealthClient(conn)
	resp, err := grpcClient.Check(ctx, &grpcHealth.HealthCheckRequest{
		Service: svc,
	})
	// the error handling is referenced from https://github.com/kubernetes/kubernetes/blob/v1.23.1/pkg/probe/grpc/grpc.go#L88-L106
	if err != nil {