@Test
public void subdomain() throws Exception {

  assertEquals("v", Urls.subdomain(Uri.parse("https://v.redd.it/fjpqnd127wf01")).get());
  assertEquals("i", Urls.subdomain(Uri.parse("https://i.redd.it/5524cd")).get());
  assertEquals(Optional.empty(), Urls.subdomain(Uri.parse("https://redd.it/5524cd")));
  assertEquals("a.b.c", Urls.subdomain(Uri.parse("https://a.b.c.rredd.it/5524cd")).get());
}