maps.Copy(metric.VariableLabels, m.VariableLabels)
	maps.Copy(metric.Histogram, m.Histogram)
	return metric
}

// Get - returns cached value always upton the configured TTL,
// once the TTL expires "read()" registered function is called
// to return the new values and updated.
func (g *MetricsGroupV2) Get() (metrics []MetricV2) {
	m, _ := g.metricsCache.Get()
	if len(m) == 0 {
		return []MetricV2{}

	})
	if err != nil {
		c.Fatalf("Err creating user admin client: %v", err)
	}
	userAdmClient.SetCustomTransport(s.TestSuiteCommon.client.Transport)

	time.Sleep(2 * time.Second) // wait for listbuckets cache to be invalidated

	accInfo, err := userAdmClient.AccountInfo(ctx, madmin.AccountOpts{})
	if err != nil {
		c.Fatalf("root user STS should be able to get account info: %v", err)
	}

	gotBuckets := set.NewStringSet()

	// since the `objectLayer==nil`  check is performed before any other checks inside the handlers.
	// The only aim is to generate an HTTP request in a way that the relevant/registered end point is evoked/called.

	nilBucket := "dummy-bucket"
	nilObject := "dummy-object"
	nilReq, err := newTestSignedRequestV4(http.MethodHead, getGetObjectURL("", nilBucket, nilObject),
		0, nil, "", "", nil)
	if err != nil {

			return false
		}
		if string(prevRData) != string(rData) {
			return false
		}
	}
	return true
}

// cache of IAM info fetched in last SiteReplicationMetaInfo call
type srIAMCache struct {
	sync.RWMutex
	lastUpdate time.Time
	srIAMInfo  madmin.SRInfo // caches IAM info
}

func (c *SiteReplicationSys) getSRCachedIAMInfo() (info madmin.SRInfo, ok bool) {
	c.iamMetaCache.RLock()

		}
		erasureSet, ok := poolInfo[d.SetIndex]
		if !ok {
			erasureSet.ID = d.SetIndex
			cache := dataUsageCache{}
			if err := cache.load(ctx, z.serverPools[d.PoolIndex].sets[d.SetIndex], dataUsageCacheName); err == nil {
				dataUsageInfo := cache.dui(dataUsageRoot, nil)
				erasureSet.ObjectsCount = dataUsageInfo.ObjectsTotalCount
				erasureSet.VersionsCount = dataUsageInfo.VersionsTotalCount

#else
  mutex_lock l(api_def_map->lock);
  if (api_def_map->update_docs_called) {
    status->status = FailedPrecondition(
        "TF_ApiDefMapPut cannot be called after TF_ApiDefMapGet has been "
        "called.");
    return;
  }
  string api_def_text(text, text_len);
  status->status = api_def_map->api_def_map.LoadApiDef(api_def_text);

		return replicateMetadata
	}

	// Compare only necessary headers
	compareKeys := []string{
		"Expires",
		"Cache-Control",
		"Content-Language",
		"Content-Disposition",
		"X-Amz-Object-Lock-Mode",
		"X-Amz-Object-Lock-Retain-Until-Date",
		"X-Amz-Object-Lock-Legal-Hold",
		"X-Amz-Website-Redirect-Location",

var supportedHeadGetReqParams = map[string]string{
	"response-expires":             xhttp.Expires,
	"response-content-type":        xhttp.ContentType,
	"response-cache-control":       xhttp.CacheControl,
	"response-content-encoding":    xhttp.ContentEncoding,
	"response-content-language":    xhttp.ContentLanguage,
	"response-content-disposition": xhttp.ContentDisposition,
}

const (

		"Server",
		"Connection",
		"Accept-Ranges",
		"Content-Range",
		"Content-Encoding",
		"Content-Length",
		"Content-Type",
		"Content-Disposition",
		"Last-Modified",
		"Content-Language",
		"Cache-Control",
		"Retry-After",
		"X-Amz-Bucket-Region",
		"Expires",
		"X-Amz*",
		"X-Amz*",
		"*",
	}
	expectedMap.Set("Vary", "Origin")