token = $token; } /** * Get the notification's channels. * * @param mixed $notifiable * @return array|string */ public function via($notifiable) { return []; } /** * Build the mail representation of the notification. * * @param mixed $notifiable * @return MailMessage */ public function toMail($notifiable) { } /** * Set a callback that should be used when building the notification mail message. * * @param Closure $callback * @return void */ public static function toMailUsing($callback) { static::$toMailCallback = $callback; } }