public void ObjectMapConfig_MapOrNull()
        {
            var config = new ObjectMapConfig();

            var  u1 = new User();
            User u2 = null;
            var  u3 = config.MapOrNull(u1, () => new User()
            {
                Int32 = 3
            });
            var u4 = config.MapOrNull(u2, () => new User()
            {
                Int32 = 3
            });

            Assert.AreEqual(u3.Int32, 3);
            Assert.AreEqual(u4, null);
        }