protected function getRecipients($notifiable, $notification, $message)
    {
        if (is_string($recipients = $notifiable->routeNotificationFor('mail', $notification))) {
            $recipients = [$recipients];
        }

        return collect($recipients)->mapWithKeys(function ($recipient, $email) {
            return is_numeric($email)
                    ? [$email => (is_string($recipient) ? $recipient : $recipient->email)]
                    : [$email => $recipient];
        })->all();
    }