public function addOrUpdateAttribute(User $user, $attribute)
    {
        $url = self::makeAttributeUrl($user->username, $user->tenantId, null, $attribute->name);
        $data = json_encode($attribute);
        $response = $this->service->prepAndSend($url, array(201, 200), 'PUT', $data, true);

        return Attribute::createFromJSON(json_decode($response));
    }