process method
Implementation
Uint8List process(Uint8List data) {
  final numBlocks = (data.length / blockSize).ceil();
  final out = Uint8List(numBlocks * blockSize);
  int offset = 0;
  for (int i = 0; i < numBlocks; i++) {
    final inputBlock = data.buffer.asByteData(offset, blockSize);
    final outputBlock = out.buffer.asByteData(offset, blockSize);
    processBlock(inputBlock, outputBlock);
    offset += blockSize;
  }
  return out;
}