public function buildMessage()
    {
        if (!empty($this->message)) {
            return $this->message;
        }

        $audioMessage = [
            'type' => MessageType::AUDIO,
            'originalContentUrl' => $this->originalContentUrl,
            'duration' => $this->duration,
        ];

        if ($this->quickReply) {
            $audioMessage['quickReply'] = $this->quickReply->buildQuickReply();
        }

        $this->message[] = $audioMessage;

        return $this->message;
    }