protected function buildJsonPayload(SlackMessage $message)
    {
        $optionalFields = array_filter([
            'channel' => data_get($message, 'channel'),
            'icon_emoji' => data_get($message, 'icon'),
            'icon_url' => data_get($message, 'image'),
            'link_names' => data_get($message, 'linkNames'),
            'unfurl_links' => data_get($message, 'unfurlLinks'),
            'unfurl_media' => data_get($message, 'unfurlMedia'),
            'username' => data_get($message, 'username'),
        ]);

        return array_merge([
            'json' => array_merge([
                'text' => $message->content,
                'attachments' => $this->attachments($message),
            ], $optionalFields),
        ], $message->http);
    }