root, cancel := WithCancel(Background())
	m := map[Context]CancelFunc{root: cancel}
	q := []Context{root}
	// Create a tree of contexts.
	for len(q) != 0 && len(m) < 100 {
		parent := q[0]
		q = q[1:]
		for i := 0; i < 4; i++ {
			ctx, cancel := WithCancel(parent)
			m[ctx] = cancel
			q = append(q, ctx)
		}
	}
	// Start all the cancels in a random order.
	var wg sync.WaitGroup

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.gradle.launcher.daemon.protocol;

public class Cancel extends Message {

	}
}

func (c *afterFuncContext) cancel(err error) {
	c.mu.Lock()
	defer c.mu.Unlock()
	if c.err != nil {
		return
	}
	c.err = err
	for _, f := range c.afterFuncs {
		go f()
	}
	c.afterFuncs = nil
}

func TestCustomContextAfterFuncCancel(t *testing.T) {
	ctx0 := &afterFuncContext{}
	ctx1, cancel := context.WithCancel(ctx0)
	defer cancel()
	ctx0.cancel(context.Canceled)
	<-ctx1.Done()
}

		// This is a long SELECT. Use the request context as the base of
		// the context timeout, but give it some time to finish. If
		// the client cancels before the query is done the query will also
		// be canceled.
		ctx, cancel := context.WithTimeout(r.Context(), 60*time.Second)
		defer cancel()

		var names []string
		rows, err := db.QueryContext(ctx, "select p.name from people as p where p.active = true;")
		if err != nil {

// first.
func WithContext(ctx context.Context) (*Group, context.Context) {
	ctx, cancel := withCancelCause(ctx)
	return &Group{cancel: cancel}, ctx
}

// Wait blocks until all function calls from the Go method have returned, then
// returns the first non-nil error (if any) from them.
func (g *Group) Wait() error {
	g.wg.Wait()
	if g.cancel != nil {
		g.cancel(g.err)
	}
	return g.err
}

        then:
        result == delegateResult

        1 * delegate.execute(work, context) >> delegateResult

        then:
        0 *_
    }

    def "cancels execution when cancellation is requested"() {
        given:
        cancellationToken.cancel()

        when:
        step.execute(work, context)

        then:
        thrown BuildCancelledException

     */
    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 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