public MainWindow()
        {
            InitializeComponent();

            root = MainWindowController.AccessDatabase();

            BuildClassTable();
        }
        private void btn_open_Click(object sender, EventArgs e)
        {
            //opens a window to select a new file to open
            OpenFileDialog openFile = new OpenFileDialog();

            openFile.InitialDirectory = @"C:\ClassRobot\";
            openFile.RestoreDirectory = true;
            openFile.Filter           = "json files (*.json)|*.json";
            openFile.Title            = "Select Class File";
            openFile.Multiselect      = false;

            if (openFile.ShowDialog() == DialogResult.OK)
            {
                string location = openFile.FileName;
                root = null;
                root = MainWindowController.AccessDatabase(location);
                BuildClassTable();
            }
        }