protected override QilNode VisitXPathPreceding(QilUnary ndPrec) {
CreateFilteredIterator(ndPrec.Child, "$$$iterPrec", typeof(XPathPrecedingIterator), XmlILMethods.XPPrecCreate, XmlILMethods.XPPrecNext,
XmlNodeKindFlags.Any, null, TriState.Unknown, null);
return ndPrec;
}