private function init()
{
$this->setPrefix($this->getConfig('prefix', 'og:'));
$this->setType($this->getConfig('type', ''));
$this->setTitle($this->getConfig('title', ''));
$this->setDescription($this->getConfig('description', ''));
$this->setSiteName($this->getConfig('site-name', ''));
$this->addProperties($this->getConfig('properties', []));
}