* Removes the document from the list of unlabeled documents in the
* corresponding tree branch.
* @param documentID Document ID.
*/
public void removeFromUnlabeledDocuments(Long documentID) {
final Object specialPath = new SpecialPath("Unlabeled documents");
if (hasNode(specialPath)) {
List<Object> children = getChildUserObjects(specialPath);
DocumentPath docPath = new DocumentPath(documentID);
if (children.contains(docPath)) {
removeUserObjectPath(new Object[] { rootObject, specialPath, docPath });