private static void InnerSearchInsideChild(Predicate <TreeNodeViewModel> predicate, bool searchAllChildren,
                                            List <TreeNodeViewModel> results, TreeNodeViewModel child)
 {
     if (predicate(child))
     {
         results.Add(child);
     }
     else
     {
         child.InnerFinding(predicate, searchAllChildren, results);
     }
 }