// additional labels for +Inf for all histogram metrics
	if expPoints := len(labels) * (len(histBuckets) + 1); expPoints != len(metrics) {
		t.Fatalf("Expected %v data points when toLowerAPILabels=false but got %v", expPoints, len(metrics))
	}

	metrics = getHistogramMetrics(ttfbHist, getBucketTTFBDistributionMD(), true, false)
	// additional labels for +Inf for all histogram metrics

}

func (bh *bucketHTTPStats) updateHTTPStats(bucket, api string, w *xhttp.ResponseRecorder) {
	if bh == nil {
		return
	}

	if w != nil {
		// Increment the prometheus http request response histogram with API, Bucket
		bucketHTTPRequestsDuration.With(prometheus.Labels{
			"api":    api,
			"bucket": bucket,
		}).Observe(w.TTFB().Seconds())
	}

	bh.Lock()
	defer bh.Unlock()

*   `tf.keras`:

    *   Changed the TensorBoard tag names produced by the
        `tf.keras.callbacks.TensorBoard` callback, so that summaries logged
        automatically for model weights now include either a `/histogram` or
        `/image` suffix in their tag names, in order to prevent tag name
        collisions across summary types.

*   When running on GPU (with cuDNN version 7.6.3 or