if (event.widget == resourcesUI &&
event.type == SWT.Expand) {
TreeItem expandedNode = (TreeItem) event.item;
TreeItem maybeDummy = expandedNode.getItem(0);
if (null == maybeDummy.getData()) {
maybeDummy.dispose();
IResource parentResource = (IResource)expandedNode.getData();
try {
populate(expandedNode, ((IContainer)parentResource).members());
} catch (CoreException e) {
throw new InternalErrorCDE("unhandled exception", e);