protected override void Arrange()
        {
            base.Arrange();

            var section = new Mocks.MockSectionWithMultipleChildCollections();
            var sectionViewModel = SectionViewModel.CreateSection(Container, "mockSection", section);
            polymorphicCollection = sectionViewModel.ChildElements
                .OfType<ElementCollectionViewModel>()
                .Where(
                c =>
                typeof(NameTypeConfigurationElementCollection<TestHandlerData, CustomTestHandlerData>).IsAssignableFrom
                    (c.ConfigurationType)).First();

        }
        protected override void Arrange()
        {
            base.Arrange();

            var section          = new Mocks.MockSectionWithMultipleChildCollections();
            var sectionViewModel = SectionViewModel.CreateSection(Container, "mockSection", section);

            polymorphicCollection = sectionViewModel.ChildElements
                                    .OfType <ElementCollectionViewModel>()
                                    .Where(
                c =>
                typeof(NameTypeConfigurationElementCollection <TestHandlerData, CustomTestHandlerData>).IsAssignableFrom
                    (c.ConfigurationType)).First();
        }