for i := 0; i < dataDown; i++ {
		disks[i] = OfflineDisk
	}
	for i := data; i < data+parityDown; i++ {
		disks[i] = OfflineDisk
	}

	b.ResetTimer()
	b.SetBytes(size)
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		writers := make([]io.Writer, len(disks))
		for i, disk := range disks {
			if disk == OfflineDisk {
				continue
			}

// list all errors that can be ignored in a bucket metadata operation.
var bucketMetadataOpIgnoredErrs = append(bucketOpIgnoredErrs, errVolumeNotFound)

// OfflineDisk represents an unavailable disk.
var OfflineDisk StorageAPI // zero value is nil

// erasureObjects - Implements ER object layer.
type erasureObjects struct {
	setDriveCount      int
	defaultParityCount int

	setIndex  int

			}
		}

		for i, r := range bitrotReaders {
			if r == nil {
				disks[i] = OfflineDisk
			}
		}
		if err == nil && !test.shouldFail {
			bitrotReaders = make([]io.ReaderAt, len(disks))
			for index, disk := range disks {
				if disk == OfflineDisk {
					continue
				}
				tillOffset := erasure.ShardFileOffset(test.offset, test.length, test.data)

			readers := make([]io.ReaderAt, len(latestDisks))
			prefer := make([]bool, len(latestDisks))
			checksumAlgo := erasureInfo.GetChecksumInfo(partNumber).Algorithm
			for i, disk := range latestDisks {
				if disk == OfflineDisk {
					continue
				}
				checksumInfo := copyPartsMetadata[i].Erasure.GetChecksumInfo(partNumber)
				partPath := pathJoin(object, srcDataDir, fmt.Sprintf("part.%d", partNumber))

	}

	metaErrs := make([]error, len(errs))

	for i, onlineDisk := range onlineDisks {
		if errs[i] != nil {
			metaErrs[i] = errs[i]
			continue
		}
		if onlineDisk == OfflineDisk {
			metaErrs[i] = errDiskNotFound
			continue
		}

		meta := partsMetadata[i]
		corrupted := false
		if filterByETag {
			corrupted = meta.Metadata["etag"] != latestMeta.Metadata["etag"]
		} else {

	s.erasureDisksMu.RLock()
	defer s.erasureDisksMu.RUnlock()

	for i := 0; i < s.setCount; i++ {
		for j := 0; j < s.setDriveCount; j++ {
			disk := s.erasureDisks[i][j]
			if disk == OfflineDisk {
				continue
			}
			if !disk.IsOnline() {
				continue
			}
			diskMap[disk.Endpoint()] = disk
		}
	}
	return diskMap
}