anchor.diff:        }
   
         // Build indices.
  -      _indicies = <int>[];
  +      _indices = <int>[];
         for (int y = 0; y < 3; y += 1) {
           for (int x = 0; x < 3; x += 1) {
             // Check if we should skip the middle rectangle.
  
positive.code:   List<Point> _vertices;
    List<Point> _textureCoordinates;
    List<Color> _colors;
    List<int> _indicies;
  
    @override
    void paint(Canvas canvas) {
  
negative.code:           // Add a rectangle (two triangles).
            int index = y * 4 + x;
  
            _indices.add(index);
            _indices.add(index + 1);
            _indices.add(index + 4);
  
            _indices.add(index + 1);
            _indices.add(index + 5);
            _indices.add(index + 4);
          }
        }
      }
  