public void Can_get_money_value()
        {
            var entity = new xts_entity
            {
                Id = Guid.NewGuid()
            };

            entity["xts_money"] = null;

            Assert.Equal(0m, entity.GetValue(e => e.xts_money));
            Assert.Equal(10m, entity.GetValue(e => e.xts_money, 10m));

            entity["xts_money"] = new Money(250m);
            Assert.Equal(250m, entity.GetValue(e => e.xts_money, 250m));
        }