private void RadCollectionView_OnGroupTapping(object sender, RadTappingEventArgs<GroupContext> e)
{
    if (e.Data.Key.ToString() == "GroupToStayPermanentlyExpanded")
    {
        e.Cancel();
    }
}


// which uses this imaginary event args with Cancel method
public class RadTappingEventArgs<T>(T data) : RadTappedEventArgs<T>(data)
{
    public void Cancel()
    {
        // prevents GroupTapped event
    }
}