/** Invoked with the result of the {@code Future} computation when it is successful. */
  void onSuccess(@ParametricNullness V result);

  /**
   * Invoked when a {@code Future} computation fails or is canceled.
   *
   * <p>If the future's {@link Future#get() get} method throws an {@link ExecutionException}, then
   * the cause is passed to this method. Any other thrown object is passed unaltered.
   */

    requests couldn't be canceled by tag. This update avoids crashing when
    `onResponse()` throws an `IOException`. That failure will now be logged
    instead of notifying the thread's uncaught exception handler. We've added a
    new API, `Call.isCanceled()` to check if a call has been canceled.

 *  New: Update `MultipartBuilder` to support content length.

	_, err := opts.UnmarshalMsg(payload)
	if err != nil {
		return grid.NewRemoteErr(err)
	}

	if !s.checkID(opts.DiskID) {
		return grid.NewRemoteErr(errDiskNotFound)
	}

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()
	return grid.NewRemoteErr(s.getStorage().WalkDir(ctx, opts, grid.WriterToChannel(ctx, out)))

    canceling calls would cause the shared HTTP/2 connection to be unnecessarily released. This
    harmed connection reuse.
 *  Fix: Ensure canceled and discarded HTTP/2 data is not permanently counted against the limited
    flow control window. We had a few bugs where window size accounting was broken when streams
    were canceled or reset.

		// because of this loop.
		for {
			if !globalCallhomeConfig.Enabled() {
				return
			}

			if !runCallhome(ctx, objAPI) {
				// callhome was disabled or context was canceled
				return
			}

			// callhome running on a different node.
			// sleep for some time and try again.
			duration := max(time.Duration(r.Float64()*float64(globalCallhomeConfig.FrequencyDur())),

	apiRequests4xxErrorsTotalMD = NewCounterMD(apiRequests4xxErrorsTotal,
		"Total number of requests with 4xx errors", "name", "type")
	apiRequestsCanceledTotalMD = NewCounterMD(apiRequestsCanceledTotal,
		"Total number of requests canceled by the client", "name", "type")

	apiRequestsTTFBSecondsDistributionMD = NewCounterMD(apiRequestsTTFBSecondsDistribution,
		"Distribution of time to first byte across API calls", "name", "type", "le")

	hstats.totalS3Requests.Inc(api)
	code := w.StatusCode

	switch {
	case code == 0:
	case code == 499:
		// 499 is a good error, shall be counted as canceled.
		hstats.totalS3Canceled.Inc(api)
	case code >= http.StatusBadRequest:
		if code >= http.StatusInternalServerError {
			hstats.totalS35xxErrors.Inc(api)
		} else {
			hstats.totalS34xxErrors.Inc(api)
		}

	// Add new service requests here.
)

// Global service signal channel.
var globalServiceSignalCh = make(chan serviceSignal)

// GlobalContext context that is canceled when server is requested to shut down.
// cancelGlobalContext can be used to indicate server shutdown.
var GlobalContext, cancelGlobalContext = context.WithCancel(context.Background())

            this.taskQueue.shutdown()
          } else {
            // When we request a graceful close also schedule a cancel of the web socket.
            val cancelAfterCloseMillis = messageOrClose.cancelAfterCloseMillis
            taskQueue.execute("$name cancel", MILLISECONDS.toNanos(cancelAfterCloseMillis)) {
              cancel()
            }
          }
        } else if (messageOrClose == null) {

}

// fanOutPutObject takes an input source reader and fans out multiple PUT operations
// based on the incoming fan-out request, a context cancellation by the caller
// would ensure all fan-out operations are canceled.
func fanOutPutObject(ctx context.Context, bucket string, objectAPI ObjectLayer, fanOutEntries []minio.PutObjectFanOutEntry, fanOutBuf []byte, opts fanOutOptions) ([]ObjectInfo, []error) {
	errs := make([]error, len(fanOutEntries))