*/
    void add(T operation);

    /**
     * Cancels all queued operations in this queue.  Any operations that have started will be allowed to complete.
     */
    void cancel();

    /**
     * Waits for all previously added operations to complete.
     * <p>
     * On failure, some effort is made to cancel any operations that have not started.
     *

	return contextName(c.Context) + ".WithCancel"
}

// cancel closes c.done, cancels each of c's children, and, if
// removeFromParent is true, removes c from its parent's children.
// cancel sets c.cause to cause if this is the first time c is canceled.
func (c *cancelCtx) cancel(removeFromParent bool, err, cause error) {
	if err == nil {
		panic("context: internal error: missing cancel error")
	}
	if cause == nil {
		cause = err
	}

     */
    void waitForCompletion();

    /**
     * Returns true if the work item is completed.
     */
    boolean isComplete();

    /**
     * Cancels this work item.
     */
    void cancel();

using ops::QueueDequeue;
using ops::QueueEnqueue;
using ops::RandomNormal;
using ops::Square;
using ops::Variable;

constexpr char kAssignOpName[] = "assign";
constexpr char kCancelOp0[] = "cancel0";
constexpr char kCancelOp1[] = "cancel1";
constexpr char kCloseOp0[] = "close0";
constexpr char kCloseOp1[] = "close1";
constexpr char kCountUpToOpName[] = "count";
constexpr char kDequeueOp0[] = "dequeue0";

     */
    void complete();

    /**
     * Whether this execution has been completed or not.
     */
    boolean isComplete();

    /**
     * Cancels this execution.
     */
    void cancel();

	timer := clock.AfterFunc(delay, fWithErrorLogging)
	return &TimedWorker{
		WorkItem:  args,
		CreatedAt: createdAt,
		FireAt:    fireAt,
		Timer:     timer,
	}
}

// Cancel cancels the execution of function by the `TimedWorker`
func (w *TimedWorker) Cancel() {
	if w != nil {
		w.Timer.Stop()
	}
}

// TimedWorkerQueue keeps a set of TimedWorkers that are still wait for execution.
type TimedWorkerQueue struct {
	sync.Mutex

func (dt *transportDialTester) roundTrip() *transportDialTesterRoundTrip {
	dt.t.Helper()
	ctx, cancel := context.WithCancel(context.Background())
	pr, pw := io.Pipe()
	rt := &transportDialTesterRoundTrip{
		t:           dt.t,
		roundTripID: dt.roundTripCount,
		done:        make(chan struct{}),
		reqBody:     pw,
		cancel:      cancel,
	}
	dt.roundTripCount++
	dt.t.Logf("RoundTrip %v: started", rt.roundTripID)

		if k, v, ok := strings.Cut(kv, "="); ok {
			envMap[k] = v
		}
	}

	s := &State{
		ctx:     ctx,
		cancel:  cancel,
		workdir: absWork,
		pwd:     absWork,
		env:     env,
		envMap:  envMap,
	}
	s.Setenv("PWD", absWork)
	return s, nil
}

// CloseAndWait cancels the State's Context and waits for any background commands to
// finish. If any remaining background command ended in an unexpected state,

	}
	initialReqCancel := req.Cancel // the user's original Request.Cancel, if any

	var cancelCtx func()
	if timeBeforeContextDeadline(deadline, oldCtx) {
		req.ctx, cancelCtx = context.WithDeadline(oldCtx, deadline)
	}

	cancel := make(chan struct{})
	req.Cancel = cancel

	doCancel := func() {
		// The second way in the func comment above:
		close(cancel)
		// The first way, used only for RoundTripper

	if err != nil {
		atomic.AddInt64(&h.failedMessages, 1)
		return
	}
	// Delete the event from store.
	return h.store.Del(key.Name)
}

// Cancel - cancels the target
func (h *Target) Cancel() {
	// If queuestore is configured, cancel it's context to
	// stop the replay go-routine.
	if h.store != nil {
		h.storeCtxCancel()
	}

	// Set logch to nil and close it.