anchor.diff:    abstract bool _processNext();
   
     _BufferList _bufferList;
  -  StringBuffer _result;
  +  List<int> _result;
   }
   
   
  
positive.code: class _StringDecoderBase implements _Decoder<String> {
    _StringDecoderBase()
        : _bufferList = new _BufferList(),
          _result = new StringBuffer();
  
    // Add UTF-8 encoded data.
    int write(List<int> buffer) {
  
negative.code:   bool _processNext() {
      while (_bufferList.length > 0) {
        int byte = _bufferList.next();
        _result.add(byte);
      }
      return true;
    }
  