private void ExpertsDeleteButton_Click(object sender, RoutedEventArgs e)
        {
            if (expertListBox.SelectedIndex != -1)
            {
                expertsNames.RemoveAt(expertListBox.SelectedIndex);

                model.DeleteAlternative(expertListBox.SelectedIndex);
                expertListBox.ItemsSource = null;
                expertListBox.ItemsSource = expertsNames;
            }
            else
            {
                MessageBox.Show("Спочатку виберіть експерта!");
            }
        }