if (root == null) {
String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NOT_SUPPORTED_ERR", null);
throw new DOMException(DOMException.NOT_SUPPORTED_ERR, msg);
}
NodeIterator iterator = new NodeIteratorImpl(this,
root,
whatToShow,
filter,
entityReferenceExpansion);
if (iterators == null) {