)

    client =
      clientTestRule
        .newClientBuilder()
        .eventListenerFactory(clientTestRule.wrap(listener))
        .connectTimeout(60, TimeUnit.SECONDS) // Deliberately exacerbate slow fallbacks.
        .dns { dnsResults }
        .fastFallback(true)
        .build()
    url =
      serverIpv4
        .url("/")
        .newBuilder()
        .host("localhost")
        .build()
  }

  companion object {
    /**
     * A network that resolves only one IP address per host. Use this when testing route selection
     * fallbacks to prevent the host machine's various IP addresses from interfering.
     */
    private val SINGLE_INET_ADDRESS_DNS =
      Dns { hostname ->
        val addresses = Dns.SYSTEM.lookup(hostname)

            </signature>
            <ignores>
              <!-- Unsafe isn't part of the documented Android API, but it is available.
                   And in cases where it's not, we have fallbacks (except maybe Striped64 (b/307807965)?). -->
              <ignore>sun.misc.Unsafe</ignore>
            </ignores>
          </configuration>
          <executions>
            <execution>

    server.protocolNegotiationEnabled = true
    server.protocols = client.protocols
  }

  /**
   * Used during tests that involve TLS connection fallback attempts. OkHttp includes the
   * TLS_FALLBACK_SCSV cipher on fallback connections. See [FallbackTestClientSocketFactory]
   * for details.
   */

    fun retryOnConnectionFailure(retryOnConnectionFailure: Boolean) =
      apply {
        this.retryOnConnectionFailure = retryOnConnectionFailure
      }

    /**
     * Configure this client to perform fast fallbacks by attempting multiple connections
     * concurrently, returning once any connection connects successfully.
     *
     * This implements Happy Eyeballs ([RFC 6555][rfc_6555]), balancing connect latency vs.

        IndexUpdateCallback callback1 = createMockCallback(10, 500);
        IndexUpdateCallback callback2 = createMockCallback(20, 1000);

        assertEquals(10L, callback1.getDocumentSize());
        assertEquals(500L, callback1.getExecuteTime());

        assertEquals(20L, callback2.getDocumentSize());
        assertEquals(1000L, callback2.getExecuteTime());

        // Test store operations
        DataStoreParams params = new DataStoreParams();

   * java.util.concurrent.CompletableFuture#thenAcceptAsync}.
   *
   * @param callback The callback to invoke when this {@code Future} is completed.
   * @param executor The executor to run {@code callback} when the future completes.
   */
  public final void addCallback(FutureCallback<? super V> callback, Executor executor) {
    Futures.addCallback(this, callback, executor);
  }

                Request
                  .Builder()
                  .url(server.url("/a"))
                  .build()
              try {
                val callbackA = RecordingCallback()
                client.newCall(requestA).enqueue(callbackA)
                callbackA.await(requestA.url).assertBody("a")
              } catch (e: Exception) {
                throw RuntimeException(e)
              }
            }

   *
   * @param future The future attach the callback to.
   * @param callback The callback to invoke when {@code future} is completed.
   * @param executor The executor to run {@code callback} when the future completes.
   * @since 10.0
   */
  public static <V extends @Nullable Object> void addCallback(
      ListenableFuture<V> future, FutureCallback<? super V> callback, Executor executor) {

        String input = "callback1\ncallback2";
        InputStream is = new ByteArrayInputStream(input.getBytes(StandardCharsets.UTF_8));

        List<String> callbackResults = new ArrayList<>();
        Consumer<String> callback = line -> callbackResults.add(line);

        InputStreamThread thread = new InputStreamThread(is, StandardCharsets.UTF_8, 10, callback);
        thread.start();
        thread.join(1000);