private static string getNodes(string xpath, string result){
            var sw = new StringWriter();
            var sets = new XmlWriterSettings{OmitXmlDeclaration = true};
            var xw = XmlWriter.Create(sw, sets);

            xw.WriteStartElement("__");
            var iter = new XPathDocument(new StringReader(result)).CreateNavigator().Select(xpath);
            while (iter.MoveNext()){
                if (iter.Current.NodeType == XPathNodeType.Attribute)
                {
                    xw.WriteElementString("_"+iter.Current.Name,iter.Current.Value);
                }
                else{
                    iter.Current.WriteSubtree(xw);
                }
            }
            xw.WriteEndElement();
            xw.Flush();
            result = sw.ToString();
            return result;
        }