Symfony\Component\Console\Style\SymfonyStyle::writeln PHP Method

    public function writeln($messages, $type = self::OUTPUT_NORMAL)
    {
        parent::writeln($messages, $type);
        $this->bufferedOutput->writeln($this->reduceBuffer($messages), $type);
    }

 /**
  * {@inheritdoc}
  *
  * @throws \LogicException
  */
 protected function execute(InputInterface $input, OutputInterface $output)
 {
     $io = new SymfonyStyle($input, $output);
     $name = $input->getArgument('name');
     if (empty($name)) {
         $io->comment('Provide the name of a bundle as the first argument of this command to dump its default configuration.');
         $io->newLine();
         $this->listBundles($output);
         return;
     }
     $extension = $this->findExtension($name);
     $configuration = $extension->getConfiguration(array(), $this->getContainerBuilder());
     $this->validateConfiguration($extension, $configuration);
     if ($name === $extension->getAlias()) {
         $message = sprintf('Default configuration for extension with alias: "%s"', $name);
     } else {
         $message = sprintf('Default configuration for "%s"', $name);
     }
     switch ($input->getOption('format')) {
         case 'yaml':
             $io->writeln(sprintf('# %s', $message));
             $dumper = new YamlReferenceDumper();
             break;
         case 'xml':
             $io->writeln(sprintf('<!-- %s -->', $message));
             $dumper = new XmlReferenceDumper();
             break;
         default:
             $io->writeln($message);
             throw new \InvalidArgumentException('Only the yaml and xml formats are supported.');
     }
     $io->writeln($dumper->dump($configuration, $extension->getNamespace()));
 }