<pre>
const (
	c1 = imag(2i)                    // imag(2i) = 2.0 is a constant
	c2 = len([10]float64{2})         // [10]float64{2} contains no function calls
	c3 = len([10]float64{c1})        // [10]float64{c1} contains no function calls
	c4 = len([10]float64{imag(2i)})  // imag(2i) is a constant and no function call is issued
	c5 = len([10]float64{imag(z)})   // invalid: imag(z) is a (non-constant) function call
)
var z complex128
</pre>

	m.Set(scannerBucketScansFinished, float64(globalScannerMetrics.lifetime(scannerMetricScanBucketDrive)))
	m.Set(scannerBucketScansStarted, float64(globalScannerMetrics.lifetime(scannerMetricScanBucketDrive)+uint64(globalScannerMetrics.activeDrives())))
	m.Set(scannerDirectoriesScanned, float64(globalScannerMetrics.lifetime(scannerMetricScanFolder)))
	m.Set(scannerObjectsScanned, float64(globalScannerMetrics.lifetime(scannerMetricScanObject)))

		if globalExpiryState != nil {
			expPendingTasks.Value = float64(globalExpiryState.PendingTasks())
			expMissedTasks.Value = float64(globalExpiryState.stats.MissedTasks())
			expMissedFreeVersions.Value = float64(globalExpiryState.stats.MissedFreeVersTasks())
			expMissedTierJournalTasks.Value = float64(globalExpiryState.stats.MissedTierJournalTasks())
			expNumWorkers.Value = float64(globalExpiryState.stats.NumWorkers())
		}

			r.opts.HeaderSize = 0
			need = int(math.Min(float64(b-hdr), float64(need))) // use remaining tokens towards payload
			tokens = need + hdr
		} else { // part of header can be accommodated
			r.opts.HeaderSize -= b - 1
			need = 1 // to ensure we read at least one byte for every Read
			tokens = b
		}
	} else { // all tokens go towards payload
		need = int(math.Min(float64(b), float64(need)))
		tokens = need
	}

			Buckets: []float64{.05, .1, .25, .5, 1, 2.5, 5, 10},
		},
		[]string{"api"},
	)
	bucketHTTPRequestsDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",
			Help:    "Time taken by requests served by current MinIO server instance per bucket",
			Buckets: []float64{.05, .1, .25, .5, 1, 2.5, 5, 10},
		},
		[]string{"api", "bucket"},
	)

		return err
	}

	m.Set(memTotal, float64(memMetrics.Total))
	m.Set(memUsed, float64(memMetrics.Used))
	usedPerc := float64(memMetrics.Used) * 100 / float64(memMetrics.Total)
	m.Set(memUsedPerc, usedPerc)
	m.Set(memFree, float64(memMetrics.Free))
	m.Set(memBuffers, float64(memMetrics.Buffers))
	m.Set(memCache, float64(memMetrics.Cache))
	m.Set(memShared, float64(memMetrics.Shared))

	storageInfo := clusterDriveMetrics.storageInfo

	m.Set(healthCapacityRawTotalBytes, float64(GetTotalCapacity(storageInfo.Disks)))
	m.Set(healthCapacityRawFreeBytes, float64(GetTotalCapacityFree(storageInfo.Disks)))
	m.Set(healthCapacityUsableTotalBytes, float64(GetTotalUsableCapacity(storageInfo.Disks, storageInfo)))
	m.Set(healthCapacityUsableFreeBytes, float64(GetTotalUsableCapacityFree(storageInfo.Disks, storageInfo)))

	return nil

	m.Set(driveUsedBytes, float64(drive.UsedSpace), labels...)
	m.Set(driveFreeBytes, float64(drive.AvailableSpace), labels...)
	m.Set(driveTotalBytes, float64(drive.TotalSpace), labels...)
	m.Set(driveUsedInodes, float64(drive.UsedInodes), labels...)
	m.Set(driveFreeInodes, float64(drive.FreeInodes), labels...)
	m.Set(driveTotalInodes, float64(drive.UsedInodes+drive.FreeInodes), labels...)

	m.readsPerSec = float64(ioStats.ReadIOs) / durationSecs
	m.readsKBPerSec = float64(ioStats.ReadSectors) * float64(sectorSize) / kib / durationSecs
	if ioStats.ReadIOs > 0 {
		m.readsAwait = float64(ioStats.ReadTicks) / float64(ioStats.ReadIOs)
	}

	m.writesPerSec = float64(ioStats.WriteIOs) / durationSecs
	m.writesKBPerSec = float64(ioStats.WriteSectors) * float64(sectorSize) / kib / durationSecs

	}
	if count > 0 {
		lrg := XferStats{
			Avg:  lavg / float64(count),
			Curr: lcurr / float64(count),
			Peak: lpeak,
		}
		sml := XferStats{
			Avg:  savg / float64(count),
			Curr: scurr / float64(count),
			Peak: speak,
		}
		qs.XferStats[Large] = lrg
		qs.XferStats[Small] = sml
		qs.XferStats[Total] = XferStats{
			Avg:  (savg + lavg) / float64(count),
			Curr: (lcurr + scurr) / float64(count),