public static TreeModel GetModel() { TreeModel treeModel = new TreeModel(); TreeItemModel treeItemModel = new TreeItemModel(treeModel) { Id = 1, Name = "Root folder", ParentId = null }; treeModel.Add(treeItemModel); treeItemModel = new TreeItemModel(treeModel) { Id = 2, Name = "Level 0 folder", ParentId = 1 }; treeModel.Add(treeItemModel); treeItemModel = new TreeItemModel(treeModel) { Id = 3, Name = "Level 1 element", ParentId = 2 }; treeModel.Add(treeItemModel); return(treeModel); }