Description:
------------
1. set session handler to tokyo_tyrant
2. start session
3. save an object with private/protected properties into $_SESSION
4. check $_SESSION

Reproduce code:
---------------
<?php
class Foo{
   private $bar;
}
session_start();
$_SESSION['foo'] = new Foo;
?>

page2.php
<?php
session_start();
var_dump($_SESSION);
?>

Expected result:
----------------
$_SESSION['foo'] is an instance of Foo

Actual result:
--------------
$_SESSION['foo'] is null