public function toiOS()
    {
        $message = [
            'apns' => [
                'aps' => [
                    'alert' => [
                        'title' => $this->title,
                        'body' => $this->body,
                    ],
                    'sound' => $this->sound,
                    'badge' => $this->badge,
                ],
            ],
        ];

        $this->formatMessage($message);

        return $message;
    }