public async Task Extended_interface_contract_changes_can_be_detected()
{
var ct = CancellationToken.None;
IStackNavigator navigator = new BlindStackNavigator();
// If the extension methods available in the abstraction package change their signatures, we get compilation errors here.
TestVM vmAfterNavigate = await navigator.Navigate(ct, () => new TestVM(), suppressTransition : false);
TestVM vmAfterNavigateAndClear = await navigator.NavigateAndClear(ct, () => new TestVM(), suppressTransition : false);
INavigableViewModel vm = navigator.GetActiveViewModel();
bool canGoBack = navigator.CanNavigateBack();
// Navigate twice so that RemovePrevious works.
await navigator.Navigate(ct, () => new TestVM(), suppressTransition : false);
await navigator.Navigate(ct, () => new TestVM(), suppressTransition : false);
await navigator.RemovePrevious(ct);
bool didNavigateBack = await navigator.TryNavigateBackTo <TestVM>(ct);
await navigator.ProcessRequest(ct, StackNavigatorRequest.GetNavigateRequest(() => new TestVM(), false, false));
IObservable <EventPattern <StackNavigatorEventArgs> > ob1 = navigator.ObserveStateChanged();
IObservable <StackNavigatorState> ob2 = navigator.ObserveCurrentState();
}