String originalName = currentThread.getName();
      currentThread.setName("Crawler " + url);
      try {
        fetch(url);
      } catch (IOException e) {
        System.out.printf("XXX: %s %s%n", url, e);
      } finally {
        currentThread.setName(originalName);
      }
    }
  }

  public void fetch(HttpUrl url) throws IOException {
    // Skip hosts that we've visited many times.

    // java.lang.reflect.InaccessibleObjectException: Unable to make member of class
    // sun.security.ssl.SSLSocketFactoryImpl accessible:  module java.base does not export
    // sun.security.ssl to unnamed module @xxx
    throw UnsupportedOperationException(
      "clientBuilder.sslSocketFactory(SSLSocketFactory) not supported on JDK 8 (>= 252) or JDK 9+",
    )
  }

  override fun newSSLContext(): SSLContext {
    return when {