Sulu\Component\Content\Repository\Content::getPropertyWithDefault PHP Method

    public function getPropertyWithDefault($name, $default = null)
    {
        if (!array_key_exists($name, $this->data)) {
            return $default;
        }
        return $this->data[$name];
    }

 /**
  * Returns new link item.
  *
  * @param Content $content
  * @param string $locale
  * @param string $scheme
  *
  * @return LinkItem
  */
 protected function getLinkItem(Content $content, $locale, $scheme)
 {
     $published = !empty($content->getPropertyWithDefault('published'));
     $url = $this->webspaceManager->findUrlByResourceLocator($content->getUrl(), $this->environment, $locale, $content->getWebspaceKey(), null, $scheme);
     return new LinkItem($content->getId(), $content->getPropertyWithDefault('title'), $url, $published);
 }