public void SetNextQuestion()
        {
            SelectedKana = null;

            _answerVisibility.Value = Visibility.Collapsed;
            _backgroundBrush.Value  = null;

            int questionIndex = _randomGenerator.Next(0, Kana.Count());

            _questionKanaItemViewModel.Value = Kana[questionIndex];

            _canSelectAnswer.Value = true;
        }