get static method
Implementation
static Future<String?> get(String url) async {
var uri = Uri.tryParse(url);
if (uri == null) throw Exception('url is not uri');
var r = await http.get(Uri.parse(url));
var body = parse(r.body);
Element? meta;
meta = body.querySelector('meta[property="og:video"]');
if (meta != null) return meta.attributes['content'];
meta = body.querySelector('meta[property="og:image"]');
return meta?.attributes['content'];
}