if (selectionBase != null) {
selectionProxy = selectionBase.getConcreteProxy();
// If we have no concrete metadata, create an empty one of the
// appropriate type
if (selectionProxy == null) {
SelectionBuilder selection = getDefaultSelectionBuilder();
selectionBase.setModelObject(selection);
// Now that we've set a concrete model object, we should
// have a concrete proxy.
selectionProxy = selectionBase.getConcreteProxy();