def _build_from_url(attrs):
        if 'url' in attrs and 'content' not in attrs:
            try:
                resp = jarr_get(attrs['url'], timeout=conf.crawler.timeout,
                                user_agent=conf.crawler.user_agent)
            except Exception:
                return attrs
            attrs.update({'url': resp.url,
                    'mimetype': resp.headers.get('content-type', None),
                    'content': base64.b64encode(resp.content).decode('utf8')})
        return attrs