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

        $sticker = [
            'type' => MessageType::STICKER,
            'packageId' => $this->packageId,
            'stickerId' => $this->stickerId,
        ];

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

        $this->message[] = $sticker;

        return $this->message;
    }