anchor.diff:    }
   
     void _close() {
  -    _data = [];
  +    _data = const [];
       _position = 0;
       _filePosition = 0;
       _fileLength = 0;
  
positive.code: 
  class _FileInputStream extends _BaseDataInputStream implements InputStream {
    _FileInputStream(String name)
        : _data = [],
          _position = 0,
          _filePosition = 0 {
      var file = new File(name);
  
negative.code:   int _position;
    int _filePosition;
    int _fileLength;
    bool _activeFillBufferCall = false;
  }
  
  
  