private static void Assert_level2_breadcrumb_values(Breadcrumb breadcrumb)
        {
            var l2Property = typeof(L1).GetProperty("L2Property");

            breadcrumb.PathShouldBe("ROOT", "Level-1-Property");
            breadcrumb.DisplayString.ShouldBe("Level-2");
            breadcrumb.PropertiesShouldBe(l2Property);
            breadcrumb.ItemTypesShouldBe<L1>();

            Assert_level1_breadcrumb_values(breadcrumb.Parent);
        }