public CharArray getNamespaceURI() {
   return _namespaces.getNamespaceURINullAllowed(getPrefix());
 }
 public CharArray getAttributeNamespace(int index) {
   if (_eventType != XMLStreamConstants.START_ELEMENT) throw illegalState("Not a start element");
   CharArray prefix = _attributes.getPrefix(index);
   return _namespaces.getNamespaceURINullAllowed(prefix);
 }