protected override QilNode VisitIs(QilBinary ndIs) {
// Generate code to push arguments onto stack
NestedVisitEnsureStack(ndIs.Left, ndIs.Right);
this.helper.Call(XmlILMethods.NavSamePos);
// navThis.IsSamePosition(navThat);
ZeroCompare(QilNodeType.Ne, true);
return ndIs;
}