private function printTitle(OutputPrinter $printer, FeatureNode $feature)
    {
        $printer->write(sprintf('%s{+keyword}%s:{-keyword}', $this->indentText, $feature->getKeyword()));

        if ($title = $feature->getTitle()) {
            $printer->write(sprintf(' %s', $title));
        }

        $printer->writeln();
    }