tracksCachedArray = null;
  public Track add(Track track) {    synchronized (this) {      Track copy;      if ((copy = getTrack(track)) == null) {        copy = new Track(track);        copy.setDownloadDir(downloadDir);        docElt.addChild(copy.getElement());        tracks.add(copy);        hash.put(copy.getKey(), copy);        /*anthony, should we be doing serial stuff to tracks done through this?*/        //copy.setTrackDatabase(this);      }      return copy;    }  }