sclass UpdatableImage extends Meta implements IIntegralImage {
  RegisteredReference<IIntegralImage> contents = new(this);
  
  *() {}
  *(IIntegralImage contents) {
    this.contents.set(contents);
  }
  
  *(BufferedImage img) {
    this(IntegralImage(img));
  }
  
  public int getWidth() { ret contents->getWidth(); }
  public int getHeight() { ret contents->getHeight(); }

  public double getIntegralValue(int x, int y, int channel) {
    ret contents->getIntegralValue(x, y, channel);
  }
    
  public double getIntegralValue(int x, int y) {
    ret contents->getIntegralValue(x, y);
  }
  
  public BufferedImage getBufferedImage() {
    ret contents->getBufferedImage();
  }
}