protected virtual void RaiseViewModelAdded(TViewModel viewModel)
 {
     ViewModelAdded?.Invoke(this, new ValueEventArgs <TViewModel>(viewModel));
     _viewModelAddedNonGeneric?.Invoke(this, new ValueEventArgs <IViewModel>(viewModel));
 }
 protected virtual void OnViewModelAdded(AudioDeviceViewModelEventArgs e)
 {
     ViewModelAdded?.Invoke(this, e);
 }