public static bool Serialize(Stream stream, SearchCriteriaList items)
        {
            try
            {
                var xs = new XmlSerializer(typeof(SearchCriteriaList));
                xs.Serialize(stream, items);
                return true;
            }
            catch
            {
            }

            return false;
        }
        public static bool Serialize(Stream stream, IEnumerable<SearchCriteriaXmlSettings> items)
        {
            try
            {
                var list = new SearchCriteriaList { Settings = items.ToList() };
                var xs = new XmlSerializer(typeof(SearchCriteriaList));
                xs.Serialize(stream, list);
                return true;
            }
            catch
            {
            }

            return false;
        }