private void button1_Click(object sender, EventArgs e)
 {
     using (var win = new AddSetWindow())
     {
         string[] ret = win.ShowWindow();
         var node = new DataNode(ret[0], sets);
         /*node.SubNodes.Add(new DataNode());
         sets.SubNodes.Add();
         */
     }
 }
        private void button1_Click(object sender, EventArgs e)
        {
            using (var win = new AddSetWindow())
            {
                string[] ret  = win.ShowWindow();
                var      node = new DataNode(ret[0], sets);

                /*node.SubNodes.Add(new DataNode());
                 * sets.SubNodes.Add();
                 */
            }
        }