anchor.diff:  
     // Iterate through data updating the hash computation for each
     // chunk.
  -  _iterate() {
  +  void _iterate() {
       var len = _pendingData.length;
       var chunkSizeInBytes = _chunkSizeInWords * _BYTES_PER_WORD;
       if (len >= chunkSizeInBytes) {
  
positive.code:   final bool _bigEndianWords;
    int _lengthInBytes = 0;
    List<int> _pendingData;
    final List<int> _currentChunk;
    final List<int> _h;
    bool _digestCalled = false;
  
    _HashBase(this._chunkSizeInWords, int digestSizeInWords, this._bigEndianWords)
        : _pendingData = [],
          _currentChunk = List.filled(_chunkSizeInWords, 0),
          _h = List.filled(digestSizeInWords, 0);
  
    // Update the hasher with more data.
    add(List<int> data) {
      if (_digestCalled) {
        throw StateError('Hash update method called after digest was retrieved');
      }
  
negative.code:     _h[1] = 0xefcdab89;
      _h[2] = 0x98badcfe;
      _h[3] = 0x10325476;
    }
  
    static const _k = [
  