}
		for i, w := range writers {
			if w == nil {
				disks[i] = nil
			}
		}

		// Get the checksums of the current part.
		bitrotReaders := make([]io.ReaderAt, len(disks))
		for index, disk := range disks {
			if disk == OfflineDisk {
				continue
			}
			tillOffset := erasure.ShardFileOffset(test.offset, test.length, test.data)