public void WriteStartNamespace(string prefix) {
Debug.Assert(prefix != null, "Invalid argument");
// Handle namespace attributes that are not sent directly to WriteNamespaceDeclaration
ConstructInEnumAttrs(XPathNodeType.Namespace);
this.nmspPrefix = prefix;
this.nmspText = string.Empty;
this.xstate = XmlState.WithinNmsp;
this.depth++;
}