public async Task IsCalledIsTheMethodIsCloseAndRemoveMethodOfTheRegionIsCalledAsync()
            {
                SetupRegionManagerBehaviorRelatedWithMainRegion();

                var fooViewModel = new FooViewModel(_serviceLocator);

                var viewLocator      = _serviceLocator.ResolveType <IViewLocator>();
                var viewModelLocator = _serviceLocator.ResolveType <IViewModelLocator>();

                viewModelLocator.Register(typeof(FooViewModelView), typeof(FooViewModel));
                viewLocator.Register(typeof(FooViewModel), typeof(FooViewModelView));

                var uiCompositionService = _serviceLocator.ResolveType <IUICompositionService>();

                uiCompositionService.Activate(fooViewModel, MainRegionName);

                await fooViewModel.CloseViewModelAsync(true);

                _mainRegionMock.Verify(region => region.Remove(It.IsAny <FooViewModelView>()), Times.Once());
            }
            public async Task IsCalledIsTheMethodIsCloseAndRemoveMethodOfTheRegionIsCalled()
            {
                SetupRegionManagerBehaviorRelatedWithMainRegion();

                var fooViewModel = new FooViewModel(_serviceLocator);

                var viewLocator = _serviceLocator.ResolveType<IViewLocator>();
                var viewModelLocator = _serviceLocator.ResolveType<IViewModelLocator>();

                viewModelLocator.Register(typeof (FooViewModelView), typeof (FooViewModel));
                viewLocator.Register(typeof (FooViewModel), typeof (FooViewModelView));

                var uiCompositionService = _serviceLocator.ResolveType<IUICompositionService>();
                uiCompositionService.Activate(fooViewModel, MainRegionName);

                await fooViewModel.CloseViewModelAsync(true);

                _mainRegionMock.Verify(region => region.Remove(It.IsAny<FooViewModelView>()), Times.Once());
            }