* @throws ParserConfigurationException If saving fails.
*/
public synchronized void saveMap(String topicFileName)
throws ParserConfigurationException {
try {
MapToDOM d = new MapToDOM();
Document dom = d.createDOM(map, topics);
String loc = topicFileName;
FileWriter out = new FileWriter(loc);
XMLOutputter outp = new XMLOutputter();
try {
outp.setFormat(Format.getPrettyFormat());