/** Implementation of load map tag from disk */
private MapTag loadMapImpl(String mapID, String originID) {
String completeID = new String(originID + "/" + mapID);
String filename = new String(mapPath + "/" + completeID);
try {
XMLFileIO mapLoader = new XMLFileIO();
XMLData d = mapLoader.readFile(filename);
if (d == null)
return null;
if (d instanceof MapTag) {
maps.put(completeID, d);
return (MapTag) d;