### Question:
BlogServiceImpl implements BlogService { @Override public Blog getBlogWithPostsNested() { SqlSession sqlSession = null; try { sqlSession = MybatisUtil.getSqlSession(); BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class); return blogMapper.getBlogWithPostsNested(); } finally { if (sqlSession != null) { sqlSession.close(); } } }  @Override Blog getBlogWithPosts(); @Override Blog getBlogWithPostsNested(); @Override Blog getBlogOneToOne(); @Override List<Blog> getAllBlog();  }### Answer:
@Test public void testGetBlogWithPostsNested() throws Exception { Blog blog = blogService.getBlogWithPostsNested(); Assert.assertNotNull(blog); }