/** Tests the addArticle function */
  public void testAddArticle() {
    Newsletter newsletter = new Newsletter("BFH Newsletter", "blablabla", 6);
    Article article =
        newsletter.addArticle("NewsletterArticle", "The newsletter project is really funny ;)");

    assertTrue("NewsletterArticle".equals(newsletter.getArticle(article.getId()).getTitle()));
  }
  /** Tests the getArticle function */
  public void testGetArticle() {
    Newsletter newsletter = new Newsletter("BFH Newsletter", "blablabla", 6);
    Article article1 =
        newsletter.addArticle("Article 1", "The newsletter project is really funny ;)");

    assertTrue(article1.equals(newsletter.getArticle(article1.getId())));
  }