code: @Api
  	public final HandlerRegistration addMapModelHandler(final MapModelHandler handler) {
  		return handlerManager.addHandler(MapModelEvent.TYPE, handler);
  	}
docs: Adds this handler to the model.
  
  @param handler
  the handler
  @return {@link com.google.gwt.event.shared.HandlerRegistration} used to remove the handler
  @since 1.6.0