ListIterator itr = myMap.getLayers(); myMap.touch();
ListIterator itr = myMap.getLayers();
	private void replaceAll(Tile f, Tile r) {				//TODO: allow for "scopes" of one or more layers, rather than all layers		ListIterator itr = myMap.getLayers();		myMap.touch();		while(itr.hasNext()) {			MapLayer layer = (MapLayer) itr.next();			layer.replaceTile(f,r);		}			}