private void folderTreeview_AfterSelect(object sender, TreeViewEventArgs e)
        {
            // sometimes there are bad selects, resulting in null node selection
            if (folderTreeview.SelectedNode == null)
            {
                return;
            }

            // only fire off method call if the selected node changed
            if (_lastSelectedNode == folderTreeview.SelectedNode)
            {
                return;
            }

            // update
            _lastSelectedNode = folderTreeview.SelectedNode;
            // clean call
            Manager.ChangedSelectedFolderNode(folderTreeview.SelectedNode);
        }