VixenApplication.ConfigElements.SaveTreeNodeState C# (CSharp) Метод

        private void SaveTreeNodeState(TreeNodeCollection collection)
        {
            foreach (TreeNode tn in collection) {
                if (tn.IsExpanded) {
                    _expandedNodes.Add(GenerateTreeNodeFullPath(tn, multiSelectTreeviewElementsGroups.PathSeparator));
                }

                if (multiSelectTreeviewElementsGroups.SelectedNodes.Contains(tn)) {
                    _selectedNodes.Add(GenerateTreeNodeFullPath(tn, multiSelectTreeviewElementsGroups.PathSeparator));
                }

                SaveTreeNodeState(tn.Nodes);
            }
        }