protected void saveSettings(final String xmlFilename) throws IOException {
final Element root = new Element("Settings");
root.addContent(viewer.stateToXml());
root.addContent(setupAssignments.toXml());
root.addContent(manualTransformation.toXml());
root.addContent(bookmarks.toXml());
final Document doc = new Document(root);
final XMLOutputter xout = new XMLOutputter(Format.getPrettyFormat());
xout.output(doc, new FileWriter(xmlFilename));
}
