Symfony\Component\Security\Core\Authentication\Token\AbstractToken::serialize PHP Method

    public function serialize()
    {
        return serialize(
            array(
                is_object($this->user) ? clone $this->user : $this->user,
                $this->authenticated,
                $this->roles,
                $this->attributes,
            )
        );
    }

 public function serialize()
 {
     return serialize(array($this->credentials, $this->manager, parent::serialize()));
 }