private void swapLanguages_Click(object sender, RoutedEventArgs e)
 {
     if (currentLanguage.SelectedItem != null && targetLanguage.SelectedItem != null)
     {
         var temp = currentLanguage.SelectedItem;
         currentLanguage.SelectedItem = targetLanguage.SelectedItem;
         targetLanguage.SelectedItem  = temp;
         SetCurrentLanguage?.Invoke(this, currentLanguage.SelectedItem as Language);
         SetTargetLanguage?.Invoke(this, targetLanguage.SelectedItem as Language);
         currentLanguageTextBox.Text = targetLanguageTextBox.Text;
     }
 }
 private void targetLanguage_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
     SetTargetLanguage?.Invoke(this, targetLanguage.SelectedItem as Language);
 }