public void clear_objects_from_the_explorer_pane()
        {
            var leftObject1 = new object();
            var leftObject2 = new object();

            registry.PlaceInExplorerPane(leftObject1, "some text");
            registry.PlaceInExplorerPane(leftObject2, "some text");

            registry.ClearTransient();

            shell.AssertWasCalled(x => x.RemoveFromExplorerPane(leftObject1));
            shell.AssertWasCalled(x => x.RemoveFromExplorerPane(leftObject2));
        }