// Verify that checksums of staleDisks
			// match expected values
			for i := range staleWriters {
				if staleWriters[i] == nil {
					continue
				}
				if !bytes.Equal(bitrotWriterSum(staleWriters[i]), bitrotWriterSum(writers[i])) {
					t.Errorf("Test %d: heal returned different bitrot checksums", i)
				}
			}
		}
	}

	}
	_, err = writer.Write([]byte("aaaaa"))
	if err != nil {
		t.Fatal(err)
	}
	if bw, ok := writer.(io.Closer); ok {
		bw.Close()
	}

	reader := newBitrotReader(disk, nil, volume, filePath, 35, bitrotAlgo, bitrotWriterSum(writer), 10)
	b := make([]byte, 10)
	if _, err = reader.ReadAt(b, 0); err != nil {
		t.Fatal(err)
	}
	if _, err = reader.ReadAt(b, 10); err != nil {
		t.Fatal(err)
	}

				continue
			}
			tillOffset := erasure.ShardFileOffset(test.offset, test.length, test.data)

			bitrotReaders[index] = newBitrotReader(disk, nil, "testbucket", "object", tillOffset, writeAlgorithm, bitrotWriterSum(writers[index]), erasure.ShardSize())
		}

		writer := bytes.NewBuffer(nil)
		_, err = erasure.Decode(context.Background(), writer, bitrotReaders, test.offset, test.length, test.data, nil)

	for _, w := range ws {
		if w != nil {
			if bw, ok := w.(io.Closer); ok {
				bw.Close()
			}
		}
	}
}

// Returns hash sum for whole-bitrot, nil for streaming-bitrot.
func bitrotWriterSum(w io.Writer) []byte {
	if bw, ok := w.(*wholeBitrotWriter); ok {
		return bw.Sum(nil)
	}
	return nil
}

// Returns the size of the file with bitrot protection