if (top != null) {
for (TextRulerLearnerController ctrl : TextRulerController.getAvailableControllers()) {
TextRulerLearnerParameter[] params = ctrl.getFactory().getAlgorithmParameters();
if (params == null || params.length == 0)
continue;
page = new AlgorithmPreferencePage(ctrl);
page.setTitle(ctrl.getName());
node = new PreferenceNode(ctrl.getID(), page);
top.add(node);
}
}