* @param filename the filename of the tileset file
*/
public void writeTileset(TileSet set, String filename) throws Exception {
OutputStream os = new FileOutputStream(filename);
Writer writer = new OutputStreamWriter(os);
XMLWriter xmlWriter = new XMLWriter(writer);
xmlWriter.startDocument();
writeTileset(set, xmlWriter, filename);
xmlWriter.endDocument();
writer.flush();
}