protected virtual XmlElement serialize(Node_Argument node)
 {
     XmlElement elem = _doc.CreateElement(node.typeName, desible1NS);
     append<Node_Identifier>(elem, node.@parameterName, "parameter name");
     append<INode_Expression>(elem, node.@value, "value");
     return elem;
 }
 //argument
 public static Argument evaluate(Node_Argument node, IScope scope)
 {
     return new Argument(
     node.parameterName == null ? null : node.parameterName.value,
     Executor.executeAny(node.value, scope));
 }