如何获得用户的详细信息与谷歌api正确

嗨，我在这段代码中有一个bug，我试图获得用户详细信息，我只需要名称，电子邮件，但代码不返回电子邮件。

<?php
include_once "templates/base.php";
session_start();
require_once ('src/Google/autoload.php');
 $client_id = '1061700181920-5i9r----something-----k3mogj328g9sed3.apps.googleusercontent.com';
 $client_secret = 'zSfeSN-----gsomething----PgtZce0uvm';
 $redirect_uri = 'http://localhost/easy_b/shop/user-example.php';
$client = new Google_Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);
$client->setRedirectUri($redirect_uri);
$client->addScope("https://www.googleapis.com/auth/plus.login");

$service = new Google_Service_Oauth2($client);
//logout
if (isset($_REQUEST['logout'])) {
  unset($_SESSION['access_token']);
}

if (isset($_GET['code'])) {
  $client->authenticate($_GET['code']);
  $_SESSION['access_token'] = $client->getAccessToken();
  $redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
  header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}
/************************************************
  If we have an access token, we can make
  requests, else we generate an authentication URL.
 ************************************************/
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
  $client->setAccessToken($_SESSION['access_token']);
} else {
  $authUrl = $client->createAuthUrl();
}
/************************************************
  If we're signed in and have a request to shorten
  a URL, then we create a new URL object, set the
  unshortened URL, and call the 'insert' method on
  the 'url' resource. Note that we re-store the
  access_token bundle, just in case anything
  changed during the request - the main thing that
  might happen here is the access token itself is
  refreshed if the application has offline access.
 ************************************************/
if ($client->getAccessToken()) {
  $user = $service->userinfo->get($_POST);
echo '<pre>';
    print_r($user);
    echo '</pre>';
  $_SESSION['access_token'] = $client->getAccessToken();
}
echo pageHeader("User Query - URL Shortener");
if (strpos($client_id, "googleusercontent") == false) {
  echo missingClientSecretsWarning();
  exit;
}
?>
<div class="box">
  <div class="request">
<?php 
if (isset($authUrl)) {
  echo "<a class='login' href='" . $authUrl . "'>Connect Me!</a>";
} else {
  echo <<<END
    <a class='logout' href='?logout'>Logout</a>
END;
}
?>
  </div>

</div>

代码返回

Google_Service_Oauth2_Userinfoplus Object
(
    [internal_gapi_mappings:protected] => Array
        (
            [familyName] => family_name
            [givenName] => given_name
            [verifiedEmail] => verified_email
        )
    [email] => 
    [familyName] => NVS
    [gender] => male
    [givenName] => Jack
    [hd] => 
    [id] => 100137049524582923700
    [link] => https://plus.google.com/100137049524582923700
    [locale] => en
    [name] => Jack NVS (LOGRomania)
    [picture] => https://lh6.googleusercontent.com/-VdyFV_RL0SE/AAAAAAAAAAI/AAAAAAAAADo/WCrZfpemELk/photo.jpg
    [verifiedEmail] => 
    [modelData:protected] => Array
        (
            [given_name] => Jack
            [family_name] => NVS
        )
    [processed:protected] => Array
        (
        )

我得到这个代码正确后，我想要它显示我的电子邮件和名称，我将在我的数据库中插入它们。但是，我如何从这个API获得适当的数据呢?