final SearchResponse response = getClient().get(c -> {
            final SearchRequestBuilder builder = c.prepareSearch(index);
            callback.accept(builder);
            builder.setFetchSource(ACCESS_RESULT_FIELDS, null);
            return builder.execute();
        });
        final OpenSearchResultList<OpenSearchAccessResult> targetList = new OpenSearchResultList<>();

    server.enqueue(MockResponse.Builder().body("hello world").build())
    val url = server.url("/").toUrl()
    val connection = url.openConnection() as HttpURLConnection
    connection.setRequestProperty("Accept-Language", "en-US")
    val reader = BufferedReader(InputStreamReader(connection.inputStream, UTF_8))
    assertThat(connection.responseCode).isEqualTo(HttpURLConnection.HTTP_OK)

            "The network name cannot be found.",
            "No more connections can be made to this remote computer at this time because there are already as many connections as the computer can accept.",
            "Indicates a Windows NT Server could not be contacted or that objects within the domain are protected such that necessary information could not be retrieved.",

* Procesamiento de datos:
  * Por ejemplo, supongamos que recibes un archivo que debe pasar por un proceso lento, puedes devolver un response de "Accepted" (HTTP 202) y procesar el archivo en segundo plano.

## Usando `BackgroundTasks` { #using-backgroundtasks }

/**
For initiating NTLM authentication (including NTLMv2). If you want to add NTLMv2 authentication support to something this is what you want to use. See the code for details. Note that JCIFS does not implement the acceptor side of NTLM authentication.
 */

public class NtlmContext {

    NtlmPasswordAuthentication auth;
    int ntlmsspFlags;
    String workstation;
    boolean isEstablished = false;

  private static <K extends Comparable<? super K>, V> ImmutableSortedMap<K, V> fromEntries(
      Entry<K, V>... entries) {
    return fromEntries(Ordering.natural(), false, entries, entries.length);
  }

  /**
   * Accepts a collection of possibly-null entries. If {@code sameComparator}, then it is assumed
   * that they do not need to be sorted or checked for dupes.
   */
  private static <K, V> ImmutableSortedMap<K, V> fromEntries(

	resp, err := target.httpClient.Do(req)
	if err != nil {
		return err
	}
	xhttp.DrainBody(resp.Body)

	if resp.StatusCode >= 200 && resp.StatusCode <= 299 {
		// accepted HTTP status codes.
		return nil
	} else if resp.StatusCode == http.StatusForbidden {
		return fmt.Errorf("%s returned '%s', please check if your auth token is correctly set", target.args.Endpoint, resp.Status)
	}

func (c *connectReq) addToken(fn AuthFn) {
	c.Token = fn()
}

func (connectReq) Op() Op {
	return OpConnect
}

type connectResp struct {
	ID             [16]byte
	Accepted       bool
	RejectedReason string
}

func (connectResp) Op() Op {
	return OpConnectResponse
}

type muxConnectError struct {
	Error string
}

func (muxConnectError) Op() Op {

    assertFalse(listenableFuture.isDone());

    listenableFuture.addListener(singleCallListener, directExecutor());
    /*
     * Don't shut down until the listenInPoolThread task has been accepted to
     * run. We want to see what happens when it's interrupted, not when it's
     * rejected.
     */
    submitSuccessful.await();
    executorService.shutdownNow();
    abstractFuture.set(DATA1);

예를 들면 다음과 같습니다.

* 작업을 수행한 후 전송되는 이메일 알림:
    * 이메일 서버에 연결하고 이메일을 전송하는 것은 (몇 초 정도) "느린" 경향이 있으므로, 응답은 즉시 반환하고 이메일 알림은 백그라운드에서 전송할 수 있습니다.
* 데이터 처리:
    * 예를 들어 처리에 오랜 시간이 걸리는 프로세스를 거쳐야 하는 파일을 받았다면, "Accepted"(HTTP 202) 응답을 반환하고 백그라운드에서 파일을 처리할 수 있습니다.

## `BackgroundTasks` 사용 { #using-backgroundtasks }

먼저 `BackgroundTasks`를 임포트하고, `BackgroundTasks` 타입 선언으로 *경로 처리 함수*에 매개변수를 정의합니다: