proxy/grpcproxy/health.go
func HandleHealth(mux *http.ServeMux, c *clientv3.Client) {
	mux.Handle(etcdhttp.PathHealth, etcdhttp.NewHealthHandler(func() etcdhttp.Health { return checkHealth(c) }))
}
func HandleHealth(mux *http.ServeMux, c *clientv3.Client) {
	mux.Handle(etcdhttp.PathHealth, etcdhttp.NewHealthHandler(func() etcdhttp.Health { return checkHealth(c) }))
}
// HandleHealth registers health handler on '/health'.