public void SetSelectBeforeUpdate()
        {
            var subClass = typeof(Inherited);
            var mapdoc = new HbmMapping();
            var mapper = new SubclassMapper(subClass, mapdoc);
            mapper.SelectBeforeUpdate(true);

            var hbmEntity = mapdoc.SubClasses[0];

            hbmEntity.SelectBeforeUpdate.Should().Be(true);
        }