public void load(InputStream is) throws IOException, ParserConfigurationException, SAXException {
   doc = db.parse(is);
   docElt = doc.getDocumentElement();
   if (docElt.getTagName().equals(docElementName)) {
     NodeList nl = docElt.getElementsByTagName(trackElementName);
     for (int i = 0; i < nl.getLength(); i++) {
       Element elt = (Element) nl.item(i);
       Track track = new Track(elt);
       tracks.add(track);
       hash.put(track.getKey(), track);
     }
   }
 }