docs: @Override public URLStreamHandler createURLStreamHandler(final String protocol) {
      if (!protocol.equals("http") && !protocol.equals("https")) return null;
  
      return new URLStreamHandler() {
        @Override protected URLConnection openConnection(URL url) {
          return open(url);
        }
  
        @Override protected URLConnection openConnection(URL url, Proxy proxy) {
          return open(url, proxy);
        }
  
        @Override protected int getDefaultPort() {
          if (protocol.equals("http")) return 80;
          if (protocol.equals("https")) return 443;
          throw new AssertionError();
        }
      };
    }