code: @Override
  	public LayerRenderer getRenderer() {
  		if (renderer == null) {
  			renderer = new DomTileLevelLayerRenderer(viewPort, this, eventBus) {
  
  				@Override
  				public TileLevelRenderer createNewScaleRenderer(int tileLevel, View view, HtmlContainer container) {
  					return new DomTileLevelRenderer(AbstractTileBasedLayer.this, tileLevel, viewPort, container,
  							getTileRenderer());
  				}
  			};
  		}
  		return renderer;
  	}
docs: ------------------------------------------------------------------------