#vulnerable code 
                              @Test
  public void testUserInfo() {
    String accessToken = System.getProperty("weixin.atoken");
    String openId = System.getProperty("weixin.openid");
    Result<com.belerweb.social.weixin.bean.User> result =
        weixin.getUser().userInfo(accessToken, openId);
    Assert.assertTrue(result.success());
    System.out.println(result.getResult().getJsonObject());
  } 
                            #location 8 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                              @Test
  public void testUserInfo() {
    String openId = System.getProperty("weixin.openid");
    Result<com.belerweb.social.weixin.bean.User> result =
        weixin.getUser().userInfo(weixin.getAccessToken().getToken(), openId);
    Assert.assertTrue(result.success());
    System.out.println(result.getResult().getJsonObject());
  }