Laravel - Notifications - Raw Data Attachments

The attachData method may be used to attach a raw string of bytes as an attachment. When calling the attachData method, you should provide the filename that should be assigned to the attachment:

     * Get the mail representation of the notification.
     * @param  mixed  $notifiable
     * @return \Illuminate\Notifications\Messages\MailMessage
    public function toMail($notifiable)
        return (new MailMessage)
                    ->attachData($this->pdf, 'name.pdf', [
                        'mime' => 'application/pdf',