optionalViewer = new CheckboxTableViewer(tblOptional);
optionalViewer.setContentProvider(ArrayContentProvider.getInstance());
optionalViewer.setLabelProvider(new ResourceLabelProvider());
optionalViewer.setSorter(new BundleSorter());
optionalViewer.addCheckStateListener(new ICheckStateListener() {
public void checkStateChanged(CheckStateChangedEvent event) {
Resource resource = (Resource) event.getElement();
if (event.getChecked()) {
checkedOptional.add(resource);
} else {