@Test
  public void testExtractPrimaryKey() throws Exception {
    final String id = "id";
    User user = new User();
    user.setId(id);

    Serializable privaryKey = ParameterUtil.extractPrimaryKey(user);

    Assert.assertEquals(privaryKey, id);
  }
  @Test
  @SuppressWarnings("unchecked")
  public void testObject() throws Exception {
    User user = new User();
    user.setId("id");
    user.setUsername("makersoft");
    user.setPassword("password");
    user.setAge(20);

    Object obj = ParameterUtil.resolve(user, shardId);
    Assert.assertTrue(obj instanceof Map);

    Map<String, Object> map = (Map<String, Object>) obj;
    Assert.assertEquals(PREFIX_VALUE, map.get(PREFIX));
    Assert.assertEquals(SUFFIX_VALUE, map.get(SUFFIX));

    Assert.assertEquals(user.getId(), map.get("id"));
    Assert.assertEquals(user.getUsername(), map.get("username"));
    Assert.assertEquals(user.getPassword(), map.get("password"));
    Assert.assertEquals(user.getAge(), map.get("age"));
  }