func (e *Erasure) ShardFileOffset(startOffset, length, totalLength int64) int64 {
	shardSize := e.ShardSize()
	shardFileSize := e.ShardFileSize(totalLength)
	endShard := (startOffset + length) / e.blockSize
	tillOffset := endShard*shardSize + shardSize
	if tillOffset > shardFileSize {
		tillOffset = shardFileSize
	}
	return tillOffset
}

// erasureSelfTest performs a self-test to ensure that erasure

	}

	return &parallelReader{
		readers:       readers,
		orgReaders:    readers,
		dataBlocks:    e.dataBlocks,
		offset:        (offset / e.blockSize) * e.ShardSize(),
		shardSize:     e.ShardSize(),
		shardFileSize: e.ShardFileSize(totalLength),
		buf:           make([][]byte, len(readers)),
		readerToBuf:   r2b,
		stashBuffer:   b,
	}
}

// Done will release any resources used by the parallelReader.

		}

		readers := make([]io.ReaderAt, len(disks))
		for i, disk := range disks {
			shardFilesize := erasure.ShardFileSize(test.size)
			readers[i] = newBitrotReader(disk, nil, "testbucket", "testobject", shardFilesize, test.algorithm, bitrotWriterSum(writers[i]), erasure.ShardSize())
		}

		// setup stale disks for the test case
		staleDisks := make([]StorageAPI, len(disks))