anchor.diff:  
           row += inc;
   
  -        if (row < 0 || _moduleCount <= row) {
  +        if (row < 0 || moduleCount <= row) {
             row -= inc;
             inc = -inc;
             break;
  
positive.code:     }
  
      // fixed module
      _modules[_moduleCount - 8][8] = (!test);
  
    }
  
    void _mapData(List<int> data, maskPattern) {
      var inc = -1;
      var row = _moduleCount - 1;
      var bitIndex = 7;
      var byteIndex = 0;
  
      for (var col = _moduleCount - 1; col > 0; col -= 2) {
  
        if (col == 6) col--;
  
  
negative.code:   void _makeImpl(bool test, int maskPattern) {
  
      _setupPositionProbePattern(0, 0);
      _setupPositionProbePattern(moduleCount - 7, 0);
      _setupPositionProbePattern(0, moduleCount - 7);
      _setupPositionAdjustPattern();
      _setupTimingPattern();
      _setupTypeInfo(test, maskPattern);
  