@Test
  public void httpClient_block() throws IOException, InterruptedException {
    final HttpClient httpClient = HttpClient.newHttpClient();
    final HttpRequest httpRequest = HttpRequest.newBuilder().uri(URI.create(JAVA11_URL)).GET().build();
    final HttpResponse<String> httpResponse = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString());
    assertEquals(httpResponse.body(), "hello");
  }

 @Test
  public void httpClient_async() throws IOException, InterruptedException {
    final HttpClient httpClient = HttpClient.newHttpClient();
    final HttpRequest httpRequest = HttpRequest.newBuilder().uri(URI.create(JAVA11_URL)).GET().build();
    CompletableFuture<HttpResponse<String>> future = httpClient.sendAsync(httpRequest, BodyHandlers.ofString());
    future.thenApply(HttpResponse::body)
      .thenAccept(log::info);

    log.info("async");
    Thread.sleep(1000); // shutdown
  }

-XX:+UseCompressedStrings

public final class String
    implements java.io.Serializable, Comparable<String>, CharSequence {

    @Stable
    private final byte[] value;
}

 private final byte coder;

public int indexOf(String str) {
        if (coder() == str.coder()) {
            return isLatin1() ? StringLatin1.indexOf(value, str.value)
                              : StringUTF16.indexOf(value, str.value);
        }
        if (coder() == LATIN1) {  // str.coder == UTF16
            return -1;
        }
        return StringUTF16.indexOfLatin1(value, str.value);
    }