anchor.diff:  
   	void updateGui(final double delta) {
   		_gui.values.forEach((element) => element.update(delta));
  +	}
  +
  +	void updateBackground(final double delta) {
  +		if (_background != null) {
  +			_starOffset += delta * 5;
  +			if (_starOffset >= _background.height()) _starOffset = 0.0;
  +		}
   	}
   
   	bool isVisible() {
  
positive.code: 
  	void renderBackground(CanvasRenderingContext2D context) {
  		if (_background != null) if (_background.isComplete()) {
  			ImageElement image =	_background.getTexture();
  			for (int y = 0; y < GameHost.height; y += _background.height()) {
  				for (int x = 0; x < GameHost.width; x += _background.width()) {
  					context.drawImage(image, x, y);
  				}
  			}
  		}
  
negative.code: 
  	/// Updates the current state
  	void update(final double delta) {
  		_current..updateBackground(delta)..update(delta)..updateGui(delta);
  	}
  
  	GameHost host() {
  