private function whenPostedArticle(PostedArticle $event)
 {
     $article = new ReadModel\Article();
     $article->id = $event->articleId();
     $article->title = $event->title();
     $article->body = $event->body();
     $this->articles[(string) $event->articleId()] = $article;
 }
 private function whenPostedArticle($data, PostedArticle $event)
 {
     $data[(string) $event->articleId()] = ['title' => $event->title(), 'commentCount' => 0];
     return $data;
 }
 private function whenPostedArticle(PostedArticle $event)
 {
     $this->articles[(string) $event->articleId()] = ['title' => $event->title(), 'commentCount' => 0];
 }
 private function whenPostedArticle(PostedArticle $postedArticle)
 {
     $this->id = $postedArticle->articleId();
 }