anchor.diff:    /// [format] defines the order of color channels in [bytes].
     /// An HTML canvas element stores colors in Format.rgba format; a Flutter
     /// Image object stores colors in Format.bgra format.
  -  /// The length of [bytes] should be format-bytes[1,2,3,4] * (width * height).
  +  /// The length of [bytes] should be (width * height) * format-byte-count,
  +  /// where format-byte-count is 1, 3, or 4 depnending on the number of
  +  /// channels in the format (luminance, rgb, rgba, etc).
  +  ///
  +  /// The native format of an image is Format.bgra. If another format
  +  /// is specified, the input data will be converted to bgra to store
  +  /// in the Image.
     ///
     /// For example, given an Html Canvas, you could create an image:
     /// var bytes = canvas.getContext('2d').getImageData(0, 0,
  
positive.code:   /// The size of the image buffer.
    int get length => data.length;
  
    /// Get a pixel from the buffer.
    int operator [](int index) => data[index];
  
    /// Set a pixel in the buffer.
    void operator []=(int index, int color) {
      data[index] = color;
    }
  
    /// Get the buffer index for the [x], [y] pixel coordinates.
    int index(int x, int y) => y * width + x;
  
    /// Is the given 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.
    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
    /// returned.
    int getPixelSafe(int x, int y) => boundsSafe(x, y) ? data[y * width + x] : 0;
  
  
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;
    }
  