private void traineeDataGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            if (traineeDataGrid.SelectedItem == null)
            {
                return;
            }
            var selectedPerson = (traineeDataGrid.SelectedItem) as Trainee;

            UpdateTraineeWindow updateTraineeWindow = new UpdateTraineeWindow(selectedPerson);

            updateTraineeWindow.ShowDialog();
        }
        private void MenuItem_Click_edit(object sender, RoutedEventArgs e)
        {
            if (traineeDataGrid.SelectedItem == null)
            {
                return;
            }
            var selectedPerson = (traineeDataGrid.SelectedItem) as Trainee;

            UpdateTraineeWindow updateTraineeWindow = new UpdateTraineeWindow(selectedPerson);

            //  updateTesterWindow.DataContext = selectedPerson;


            updateTraineeWindow.ShowDialog();
        }