anchor.diff:    /// The size of the image buffer.
     int get length => data.length;
   
  -  /// Get a pixel from the buffer.
  +  /// Get a pixel from the buffer. No range checking is done.
     int operator [](int index) => data[index];
   
  -  /// Set a pixel in the buffer.
  +  /// Set a pixel in the buffer. No range checking is done.
     void operator []=(int index, int color) {
       data[index] = color;
     }
   
     /// Get the buffer index for the [x], [y] pixel coordinates.
  +  /// No range checking is done.
     int index(int x, int y) => y * width + x;
   
  -  /// Is the given pixel coordinates within the resolution of the image.
  +  /// Is the given [x], [y] pixel coordinates within the resolution of the image.
     bool boundsSafe(int x, int y) => x >= 0 && x < width && y >= 0 && y < height;
   
     /// Get the pixel from the given [x], [y] coordinate. Color is encoded in a
  -  /// Uint32 as 0xAARRGGBB.
  +  /// Uint32 as #AARRGGBB. No range checking is done.
     int getPixel(int x, int y) => data[y * width + x];
   
     /// Get the pixel from the given [x], [y] coordinate. Color is encoded in a
  -  /// Uint32 as 0xAARRGGBB. If the pixel coordinates are out of bounds, 0 is
  +  /// Uint32 as #AARRGGBB. If the pixel coordinates are out of bounds, 0 is
     /// returned.
     int getPixelSafe(int x, int y) => boundsSafe(x, y) ? data[y * width + x] : 0;
   
  
positive.code:     int _linear(int Icc, int Inc, int Icn, int Inn) {
        return (Icc +
                dx * (Inc - Icc + dy * (Icc + Inn - Icn - Inc)) +
                dy * (Icn - Icc))
            .toInt();
      }
  
      int Icc = getPixelSafe(x, y);
  
negative.code:   }
  
    /// Set the pixel at the given [x], [y] coordinate to the [color].
    /// No range checking is done.
    void setPixel(int x, int y, int color) {
      data[y * width + x] = color;
    }
  