protected override void Initialize()
        {
            id = 1;

            using (var tx = Session.BeginTransaction())
            {
                var entity = new ParentDerived()
                {
                    Id = id
                };
                Session.Save(entity);
                Session.Flush();

                tx.Commit();
            }
            var q = Cfg.GetClassMapping(typeof(ParentBase));
            var w = Cfg.GetClassMapping(typeof(ParentDerived));
            var e = Cfg.GetClassMapping(typeof(Child));
            var c = Cfg.GetCollectionMapping(typeof(ParentBase).FullName + "." + "Children");
        }