timeout := newDynamicTimeout(time.Minute, time.Second)

	initial := timeout.Timeout()

	for i := 0; i < dynamicTimeoutLogSize; i++ {
		timeout.LogSuccess(20 * time.Second)
	}

	adjusted := timeout.Timeout()

	for i := 0; i < dynamicTimeoutLogSize; i++ {
		timeout.LogSuccess(20 * time.Second)
	}

	adjustedAgain := timeout.Timeout()

	if initial <= adjusted || adjusted <= adjustedAgain {

		defer cancel()
		if err := newCtx.Err(); err == context.Canceled {
			return LockContext{ctx: ctx, cancel: func() {}}, err
		}
		return LockContext{ctx: ctx, cancel: func() {}}, OperationTimedOut{}
	}
	timeout.LogSuccess(UTCNow().Sub(start))
	return LockContext{ctx: newCtx, cancel: cancel}, nil
}

// Unlock - block until write lock is released.
func (di *distLockInstance) Unlock(lc LockContext) {
	if lc.cancel != nil {

	return time.Duration(atomic.LoadInt64(&dt.timeout))
}

func (dt *dynamicTimeout) RetryInterval() time.Duration {
	return dt.retryInterval
}

// LogSuccess logs the duration of a successful action that
// did not hit the timeout
func (dt *dynamicTimeout) LogSuccess(duration time.Duration) {
	dt.logEntry(duration)
}

// LogFailure logs an action that hit the timeout
func (dt *dynamicTimeout) LogFailure() {

	d := diskHealthTracker{
		lastSuccess: time.Now().UnixNano(),
		lastStarted: time.Now().UnixNano(),
	}
	d.status.Store(diskHealthOK)
	return &d
}

// logSuccess will update the last successful operation time.
func (d *diskHealthTracker) logSuccess() {
	atomic.StoreInt64(&d.lastSuccess, time.Now().UnixNano())
}

func (d *diskHealthTracker) isFaulty() bool {
	return d.status.Load() == diskHealthFaulty
}

)

func TestTierMetrics(t *testing.T) {
	tier := "WARM-1"
	globalTierMetrics.Observe(tier, 200*time.Millisecond)
	expSuccess := 10
	expFailure := 5
	for i := 0; i < expSuccess; i++ {
		globalTierMetrics.logSuccess(tier)
	}
	for i := 0; i < expFailure; i++ {
		globalTierMetrics.logFailure(tier)
	}
	metrics := globalTierMetrics.Report()
	var succ, fail float64
	for _, metric := range metrics {

	}, []string{"tier"}),
}

func (t *tierMetrics) Observe(tier string, dur time.Duration) {
	t.histogram.With(prometheus.Labels{"tier": tier}).Observe(dur.Seconds())
}

func (t *tierMetrics) logSuccess(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.success++
	t.requestsCount[tier] = stat
}

func (t *tierMetrics) logFailure(tier string) {
	t.Lock()

			OutputBytes: bytes,
		}

		if err == nil {
			since := time.Since(startTime)
			op.TimeToResponseNS = since.Nanoseconds()
			globalTierMetrics.Observe(tier, since)
			globalTierMetrics.logSuccess(tier)
		} else {
			op.Error = err.Error()
			globalTierMetrics.logFailure(tier)
		}

		logger.GetReqInfo(ctx).AppendTags("tierStats", op)
	}
}