anchor.diff:  
   void main() async {
     winrtInitialize();
  -
  -  final allocator = Arena();
  +  final pIndex = calloc<Uint32>();
   
     final object = CreateObject(
         'Windows.Storage.Pickers.FileOpenPicker', IID_IFileOpenPicker);
  
positive.code:   final vectorView = filters.GetView;
    print('VectorView has ${vectorView.length} elements.');
  
    final pIndex = allocator<Uint32>();
    var containsElement = filters.IndexOf('.jpeg', pIndex);
    print(containsElement
        ? 'The index of ".jpeg" is ${pIndex.value}.'
  
negative.code:   filters.Clear();
    print('Vector has ${filters.Size} elements.');
  
    free(pIndex);
    free(filters.ptr);
    winrtUninitialize();
  }
  