private void btnStart_Click(object sender, RoutedEventArgs e)
        {
            stopwatch.Start();
            dispatcher.Start();
            stopwatch.Restart();
            ComboBoxItem selectedDifficulty = (ComboBoxItem)btnLevel.SelectedItem;
            string       difficulty         = selectedDifficulty.Content.ToString();

            Console.WriteLine(difficulty);
            Sudoku = new SudokuGenerator(difficulty);
            Sudoku.StartGame();
            Sudoku.SetUndoStack();
            Sudoku.SetRedoStack();
            InsertIntoGameBoard(Sudoku);
            numberOfGames++;
            TextBoxSolutionsNumber.Text = $"True Solutions:{numberOfTrueGames}";
        }