@Override
    protected void deserializeItemsFromByteArray(byte[] byteArray, AtomicInteger currentIndex,
                                                 int lengthOfItems) throws IOException {
        if (lengthOfItems != 8) {
            throw new StreamObjectParseErrorException(currentIndex.get(), "DataSize",
                    "Stream Object over-parse error", null);
        }

        this.dataSize = LittleEndianBitConverter.toUInt64(byteArray, currentIndex.get());
        currentIndex.addAndGet(8);
    }
Used to de-serialize the element.

@param byteArray     A Byte array
@param currentIndex  Start position
@param lengthOfItems The length of the items
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/onenote/fsshttpb/streamobj/DataSizeObject.java