public function deleteSession($user_id)
    {
        if (!isset($_SESSION['admin_sid'])) {
            return true;
        }
        $user_id = (int)$user_id;

        $sessions = new UsersSessionEntityRepository();
        $sessions->setWhereUserId($user_id);
        $sessions->setWhereSid($_SESSION['admin_sid']);
        $sessions->deleteObjectCollection();

        return true;
    }