* exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */
  fun enqueue(responseCallback: Callback)

  /** Cancels the request, if possible. Requests that are already complete cannot be canceled. */
  fun cancel()

  /**
   * Returns true if this call has been either [executed][execute] or [enqueued][enqueue]. It is an
   * error to execute a call more than once.
   */

   *
   * <p>This differs from {@link #successfulAsList(ListenableFuture[])} in that it will return a
   * failed future if any of the items fails.
   *
   * <p>Canceling this future will attempt to cancel all the component futures, and if any of the
   * provided futures fails or is canceled, this one is, too.
   *
   * @param futures futures to combine
   * @return a future that provides a list of the results of the component futures

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

	if !dm.GetLock(ctx, cancel, id, source, Options{Timeout: 5 * time.Minute}) {
		t.Fatal("GetLock() should be successful")
	}

	// Make it run twice.
	timer := time.NewTimer(testDrwMutexRefreshInterval * 2)

	select {
	case <-ctx.Done():
		t.Fatal("Lock context canceled which is not expected")
	case <-timer.C:
	}

        else -> Socket(route.proxy)
      }
    this.rawSocket = rawSocket

    // Handle the race where cancel() precedes connectSocket(). We don't want to miss a cancel.
    if (canceled) {
      throw IOException("canceled")
    }

    rawSocket.soTimeout = socketReadTimeoutMillis
    try {

        }
      } catch (e: Exception) {
        val exception =
          when {
            canceled -> IOException("canceled", e)
            else -> e
          }
        listener.onFailure(this, exception, response)
        return
      }
      if (canceled) {
        listener.onFailure(this, IOException("canceled"), response)
      } else {
        listener.onClosed(this)
      }
    }
  }

   *
   * <p>This differs from {@link #successfulAsList(ListenableFuture[])} in that it will return a
   * failed future if any of the items fails.
   *
   * <p>Canceling this future will attempt to cancel all the component futures, and if any of the
   * provided futures fails or is canceled, this one is, too.
   *
   * @param futures futures to combine
   * @return a future that provides a list of the results of the component futures

          ConnectResult(this, nextPlan = connectTcpNextPlan, throwable = tcpConnectThrowable)
        }
        canceled -> {
          events += "plan $id TCP connect canceled"
          ConnectResult(this, nextPlan = connectTcpNextPlan, throwable = IOException("canceled"))
        }
        connectTcpNextPlan != null -> {
          events += "plan $id needs follow-up"

    stream = http2Connection.newStream(requestHeaders, hasRequestBody)
    // We may have been asked to cancel while creating the new stream and sending the request
    // headers, but there was still no stream to close.
    if (canceled) {
      stream!!.closeLater(ErrorCode.CANCEL)
      throw IOException("Canceled")
    }
    stream!!.readTimeout().timeout(chain.readTimeoutMillis.toLong(), TimeUnit.MILLISECONDS)

    taskFaker.advanceUntil(500.ms)
    assertEvents(
      "take plan 2",
      "plan 0 cancel",
      "plan 1 cancel",
    )

    taskFaker.advanceUntil(510.ms)
    assertEvents(
      "plan 1 TCP connect canceled",
    )

    taskFaker.advanceUntil(520.ms)
    assertEvents(
      "plan 0 TCP connect canceled",
    )
  }

  @Test
  fun takeMultipleConnections() {

			return time.Now(), slowCaller(ctx)
		},
	)

	ctx, cancel := context.WithCancel(context.Background())
	cancel() // cancel context to test.

	_, err := cache.GetWithCtx(ctx)
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("expected context.Canceled err, got %v", err)
	}

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

	t1, err := cache.GetWithCtx(ctx)
	if err != nil {