private static void ExecutedStrikethroughCommand(object sender, ExecutedRoutedEventArgs e)
        {
            ContextTextFormatter formatter = (ContextTextFormatter)sender;

            if (formatter.strikethroughButton.IsChecked == true)
            {
                TextEditing.AddTextDecoration(TextDecorations.Strikethrough);
            }
            else
            {
                TextEditing.RemoveTextDecoration(TextDecorations.Strikethrough);
            }
        }
        private static void ExecutedUnderlineCommand(object sender, ExecutedRoutedEventArgs e)
        {
            ContextTextFormatter formatter = (ContextTextFormatter)sender;

            if (formatter.underlineButton.IsChecked == true)
            {
                TextEditing.AddTextDecoration(TextDecorations.Underline);
            }
            else
            {
                TextEditing.RemoveTextDecoration(TextDecorations.Underline);
            }
        }