* {@link #getDirty()} cannot be transformed using the
* {@link #collectionType}
* @return true when the collection has been populated
*/
private Boolean populateObservableCollection() throws Throwable {
final Observable oc = getCollectionObservable();
Boolean changed = null;
if (isList() || isSet()) {
addRemoveCollectionListener(oc, false);
Collection<?> items = (Collection<?>) getDirty();
if (items == null) {