private void ValidateWhitespaceNode ()
{
// VC Standalone Document Declaration (2.9)
if (this.isStandalone && DTD != null && elementStack.Count > 0) {
DTDElementDeclaration elem = DTD.ElementDecls [elementStack.Peek () as string];
if (elem != null && !elem.IsInternalSubset && !elem.IsMixedContent && !elem.IsAny && !elem.IsEmpty)
HandleError ("In a standalone document, whitespace cannot appear in an element which is declared to contain only element children.", XmlSeverityType.Error);
}
}