public function addArticle(ArticleEntity $article, $language)
{
$article = new \Newscoop\Subscription\Article($this->subscription, $article);
$article->setStartDate($this->startDate);
$article->setDays($this->days);
$article->setPaidDays($this->paidDays);
$article->setLanguage($language);
$this->articles[$article->getArticleNumber()] = $article;
}