public void addMixin(String s) throws NoSuchNodeTypeException, VersionException, ConstraintViolationException, LockException, RepositoryException {
try {
CollectionImpl collec = (CollectionImpl) registrySession.getUserRegistry().get(nodePath);
if (collec.getPropertyValues("jcr:mixinTypes") == null) {
List list = new ArrayList();
list.add(s);
collec.setProperty("jcr:mixinTypes", list);
} else {
collec.getPropertyValues("jcr:mixinTypes").add(s);
}
registrySession.getUserRegistry().put(nodePath, collec);
} catch (RegistryException e) {