histBuckets := []float64{0.05, 0.1, 0.25, 0.5, 0.75}
	labels := []string{"GetObject", "PutObject", "CopyObject", "CompleteMultipartUpload"}
	ttfbHist := prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",
			Help:    "Time taken by requests served by current MinIO server instance",
			Buckets: histBuckets,
		},
		[]string{"api"},
	)
	observations := []struct {
		val   float64
		label string
	}{
		{