metricsRouter.Handle(prometheusMetricsV2NodePath, auth(metricsNodeHandler()))
	metricsRouter.Handle(prometheusMetricsV2ResourcePath, auth(metricsResourceHandler()))

	// Metrics v3
	metricsV3Server := newMetricsV3Server(auth)

	// Register metrics v3 handler. It also accepts an optional query
	// parameter `?list` - see handler for details.

	auth     func(http.Handler) http.Handler

	metricsData *metricsV3Collection
}

var (
	globalMetricsV3CollectorPaths []collectorPath
	globalMetricsV3Once           sync.Once
)

func newMetricsV3Server(auth func(h http.Handler) http.Handler) *metricsV3Server {
	registry := prometheus.NewRegistry()
	metricGroups := newMetricGroups(registry)
	globalMetricsV3Once.Do(func() {