* input future and that of the future returned by the chain function. That is, if the returned
   * {@code Future} is cancelled, it will attempt to cancel the other two, and if either of the
   * other two is cancelled, the returned {@code Future} will receive a callback in which it will
   * attempt to cancel itself.
   *
   * @param input The future to transform

   */
  override fun cancel() {
    if (canceled) return // Already canceled.

    canceled = true
    exchange?.cancel()
    for (plan in plansToCancel) {
      plan.cancel()
    }

    eventListener.canceled(this)
  }

  override fun isCanceled(): Boolean = canceled

  override fun execute(): Response {

        }
      } 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)
      }
    }
  }

   * the event source has already been closed or canceled.
   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */

      @Override
      @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
      public void cancel(boolean mayInterruptIfRunning) {
        /*
         * Lock to ensure that a task cannot be rescheduled while a cancel is ongoing.
         *
         * In theory, cancel() could execute arbitrary listeners -- bad to do while holding a lock.

    // stop it.
    blockingCallable.waitForStart();

    // This time, cancel the future for the first task. The task remains running, only the future
    // is cancelled.
    future1.cancel(false);

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    // (This is the assertion that fails.)

   * input future and that of the future returned by the chain function. That is, if the returned
   * {@code Future} is cancelled, it will attempt to cancel the other two, and if either of the
   * other two is cancelled, the returned {@code Future} will receive a callback in which it will
   * attempt to cancel itself.
   *
   * <p>This method is similar to {@link java.util.concurrent.CompletableFuture#thenCompose} and

      @Override
      @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
      public void cancel(boolean mayInterruptIfRunning) {
        /*
         * Lock to ensure that a task cannot be rescheduled while a cancel is ongoing.
         *
         * In theory, cancel() could execute arbitrary listeners -- bad to do while holding a lock.

        .build(),
    )
    listener.enqueueCancel() // Will cancel in onOpen().
    val request = Request.Builder().url(server.url("/")).build()
    val response = client.newCall(request).execute()
    response.processEventSource(listener)
    listener.assertOpen()
    listener.assertFailure("canceled")
  }

  @Test
  fun failureWith401IsReadable() {
    server.enqueue(
      MockResponse(

        val startNanos = System.nanoTime()
        val call = client.newCall(request)

        // Schedule a job to cancel the call in 1 second.
        executor.schedule({
          System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f)
          call.cancel()
          System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f)
        }, 1, TimeUnit.SECONDS)