private void AddButton_OnClick(object sender, RoutedEventArgs e)
        {
            var addEmployeeWindow = new AddEditEmployeeWindow();
            addEmployeeWindow.ShowDialog();

            _transactionCacheCao.CreateRecord(addEmployeeWindow.Employee);
            UpdateListBox();
        }
        private void EditButton_OnClick(object sender, RoutedEventArgs e)
        {
            if (LbEmployees.SelectedIndex >= 0)
            {
                var editEmployeeWindow = new AddEditEmployeeWindow((Employee)LbEmployees.SelectedItem);
                editEmployeeWindow.ShowDialog();

                _transactionCacheCao.UpdateRecord(editEmployeeWindow.Employee);
                UpdateListBox();
            }
        }