@Test
  public void testdeleteArticle() {
    String url = "test.at";
    int id = 5;
    Article ar = new Article();
    ar.setUrl(url);
    ar.setId(id);

    EntityManager mockEm = createMock(EntityManager.class);
    expect(mockEm.find(Article.class, ar.getId())).andReturn(ar);
    mockEm.remove(ar);
    replay(mockEm);

    ArticleDao aDAO = new ArticleDao();
    aDAO.setEntityManager(mockEm);
    // Test
    aDAO.deleteArticle(ar.getId());
    // Verify
    verify(mockEm);
  }