public async Task StopTracking_Should_return_from_execution_When_geolocator_is_not_already_listening() { _geolocator.IsListening.Returns(false); await _trackerService.StopTracking(); await _geolocator.DidNotReceive().StopListeningAsync(); _geolocator.DidNotReceive().PositionChanged -= Arg.Any <EventHandler <PositionEventArgs> >(); }