public void Save(Visitor visitor)
 {
     using (ISession session = DataConfig.GetSession())
     {
         session.BeginTransaction();
         session.SaveOrUpdate(visitor);
         session.Transaction.Commit();
     }
 }
        public Visitor[] GetRecentVisitors(int numberOfVisitors)
        {
            using (ISession session = DataConfig.GetSession())
            {
                Visitor[] recentVisitors =
                    session.Query <Visitor>()
                    .OrderByDescending(v => v.VisitDate)
                    .Take(numberOfVisitors)
                    .ToArray();

                return(recentVisitors);
            }
        }