def METHOD_NAME(self, obj):
    """urls for each media's pages."""
    if obj.uploaded_on is None or obj.nb_pages is None:
        return None
    urls = {}
    stamp = time_utils.to_timestamp(obj.uploaded_on)
    base = (
        f"{settings.AWS_S3_URL_PROTOCOL}://{settings.CLOUDFRONT_DOMAIN}/"
        f"{obj.video_id}/sharedlivemedia/{obj.pk}/{stamp}"
    )
    if settings.CLOUDFRONT_SIGNED_URLS_ACTIVE:
        params = get_video_cloudfront_url_params(obj.video_id)
    pages = {}
    for page_number in range(1, obj.nb_pages + 1):
        url = f"{base:s}_{page_number:d}.svg"
        if settings.CLOUDFRONT_SIGNED_URLS_ACTIVE:
            url = cloudfront_utils.build_signed_url(url, params)
        pages[page_number] = url
    urls["pages"] = pages
    # Downloadable link can be generated only when cloudfront request is signed
    if (
        self.context.get("is_admin") or obj.show_download
    ) and settings.CLOUDFRONT_SIGNED_URLS_ACTIVE:
        extension = f".{obj.extension}" if obj.extension else ""
        urls["media"] = cloudfront_utils.build_signed_url(
            f"{base}{extension}?response-content-disposition="
            f"{quote_plus('attachment; filename=' + self.get_filename(obj))}",
            params,
        )
    return urls