public XamlDirective (string xamlNamespace, string name) : this (new string [] {xamlNamespace}, name, new XamlType (typeof (object), new XamlSchemaContext (new XamlSchemaContextSettings ())), null, AllowedMemberLocations.Any) { if (xamlNamespace == null) throw new ArgumentNullException ("xamlNamespace"); is_unknown = true; }