val response1 = call1.execute()
    waitForDataFrames(Http2Connection.OKHTTP_CLIENT_WINDOW_SIZE)

    // Cancel the call and discard what we've buffered for the response body. This should free up
    // the connection flow-control window so new requests can proceed.
    call1.cancel()
    assertThat(
      response1.body.source().discard(1, TimeUnit.SECONDS),
      "Call should not have completed successfully.",

	// Updates must be closed before we return.
	defer xioutil.SafeClose(updates)

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	var wg sync.WaitGroup
	var mu sync.Mutex
	var results []dataUsageCache
	var firstErr error

	allBuckets, err := z.ListBuckets(ctx, BucketOptions{})
	if err != nil {

    // Play it back.
    connect(peer, PushObserver.CANCEL, Http2Connection.Listener.REFUSE_INCOMING_STREAMS)

    // Verify the peer received what was expected.
    val rstStream = peer.takeFrame()
    assertThat(rstStream.type).isEqualTo(Http2.TYPE_RST_STREAM)
    assertThat(rstStream.streamId).isEqualTo(2)
    assertThat(rstStream.errorCode).isEqualTo(ErrorCode.CANCEL)
  }

  /**

    step2Waiter.awaitStarted();

    // Everything should still be open.
    assertStillOpen(closeable1, closeable2, closeable3, closeable4);

    // Cancel step 3, resume step 2, and pause in step 4.
    assertWithMessage("step3.cancel()").that(step3.cancel(false)).isTrue();
    step2Waiter.awaitReturned();
    step4Waiter.awaitStarted();

    // Step 1 is not cancelled because it was done.

    EntryTransformer<String, String, String> concat =
        new EntryTransformer<String, String, String>() {
          @Override
          public String transformEntry(String key, String value) {
            return key + value;
          }
        };
    Map<String, String> transformed = transformEntries(map, concat);

    assertEquals(ImmutableMap.of("a", "a4", "b", "b9"), transformed);

    EntryTransformer<String, String, String> concat =
        new EntryTransformer<String, String, String>() {
          @Override
          public String transformEntry(String key, String value) {
            return key + value;
          }
        };
    Map<String, String> transformed = transformEntries(map, concat);

    assertEquals(ImmutableMap.of("a", "a4", "b", "b9"), transformed);

    step2Waiter.awaitStarted();

    // Everything should still be open.
    assertStillOpen(closeable1, closeable2, closeable3, closeable4);

    // Cancel step 3, resume step 2, and pause in step 4.
    assertWithMessage("step3.cancel()").that(step3.cancel(false)).isTrue();
    step2Waiter.awaitReturned();
    step4Waiter.awaitStarted();

    // Step 1 is not cancelled because it was done.

                boolean recursive) {
            List<Callable<InterimResult>> tasks = pomFiles.stream()
                    .map(pomFile -> ((Callable<InterimResult>)
                            () -> build(projectIndex, pomFile, concat(aggregatorFiles, pomFile), root, recursive)))
                    .collect(Collectors.toList());
            try {
                List<Future<InterimResult>> futures = executor.invokeAll(tasks);

    )
    val call =
      client.newCall(
        Request.Builder()
          .url(server.url("/"))
          .build(),
      )
    call.cancel()
    call.cancel()
    assertThat(listener.recordedEventTypes()).containsExactly("Canceled")
  }

  private fun assertSuccessfulEventOrder(responseMatcher: Matcher<Response?>?) {
    val call =
      client.newCall(
        Request.Builder()

// order, and type) the op declaration.  For example, the "Concat" op
// has registration:
//   REGISTER_OP("Concat")
//       .Input("concat_dim: int32")
//       .Input("values: N * T")
//       .Output("output: T")
//       .Attr("N: int >= 2")
//       .Attr("T: type");
// that defines two inputs, "concat_dim" and "values" (in that order).