private static void UnmarshallResult(XmlUnmarshallerContext context, DescribeIndexFieldsResponse response)
        {
            
            int originalDepth = context.CurrentDepth;
            int targetDepth = originalDepth + 1;
            
            if (context.IsStartOfDocument) 
               targetDepth += 2;
            
            while (context.ReadAtDepth(originalDepth))
            {
                if (context.IsStartElement || context.IsAttribute)
                {

                    if (context.TestExpression("IndexFields/member", targetDepth))
                    {
                        var unmarshaller = IndexFieldStatusUnmarshaller.Instance;
                        var item = unmarshaller.Unmarshall(context);
                        response.IndexFields.Add(item);
                        continue;
                    }
                } 
           }

            return;
        }
        private static void UnmarshallResult(XmlUnmarshallerContext context,DescribeIndexFieldsResponse response)
        {
            
            int originalDepth = context.CurrentDepth;
            int targetDepth = originalDepth + 1;
            
            if (context.IsStartOfDocument) 
               targetDepth += 2;
            
            while (context.Read())
            {
                if (context.IsStartElement || context.IsAttribute)
                {
                    if (context.TestExpression("IndexFields/member", targetDepth))
                    {
                        response.IndexFields.Add(IndexFieldStatusUnmarshaller.GetInstance().Unmarshall(context));
                            
                        continue;
                    }
                }
                else if (context.IsEndElement && context.CurrentDepth < originalDepth)
                {
                    return;
                }
            }
                            


            return;
        }
        public override AmazonWebServiceResponse Unmarshall(XmlUnmarshallerContext context)
        {
            DescribeIndexFieldsResponse response = new DescribeIndexFieldsResponse();

            context.Read();
            int targetDepth = context.CurrentDepth;
            while (context.ReadAtDepth(targetDepth))
            {
                if (context.IsStartElement)
                {                    
                    if(context.TestExpression("DescribeIndexFieldsResult", 2))
                    {
                        UnmarshallResult(context, response);                        
                        continue;
                    }
                    
                    if (context.TestExpression("ResponseMetadata", 2))
                    {
                        response.ResponseMetadata = ResponseMetadataUnmarshaller.Instance.Unmarshall(context);
                    }
                }
            }

            return response;
        }