if (values.isEmpty()) {
throw new RequestException("Values are missing");
}
// read optional filter
final NodeFilter nf = req.getNodeFilter();
// convert namespace/values to NamespaceValue objects for delegation
List<NamespaceValue> nvs = new ArrayList<NamespaceValue>(values.size());
for (String s : values) {
NamespaceValue nv = OBJECT_FACTORY.createNamespaceValue();