timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
	defer cancel()

	_, err := client.Delete(timeoutCtx, key)
	etcdLogIf(ctx, err)
	return etcdErrToErr(err, client.Endpoints())
}

func readKeyEtcd(ctx context.Context, client *etcd.Client, key string) ([]byte, error) {
	timeoutCtx, cancel := context.WithTimeout(ctx, defaultContextTimeout)
	defer cancel()
	resp, err := client.Get(timeoutCtx, key)

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.
 * Keep whichever TCP connection succeeds first and cancel all the others.

	ctx := newContext(r, w, "ClusterCheckHandler")

	objLayer := checkHealth(w)
	if objLayer == nil {
		return
	}

	ctx, cancel := context.WithTimeout(ctx, globalAPIConfig.getClusterDeadline())
	defer cancel()

	opts := HealthOptions{
		Maintenance:    r.Form.Get("maintenance") == "true",
		DeploymentType: r.Form.Get("deployment-type"),
	}
	result := objLayer.Health(ctx, opts)

type LockContext struct {
	ctx    context.Context
	cancel context.CancelFunc
}

// Context returns lock context
func (l LockContext) Context() context.Context {
	return l.ctx
}

// Cancel function calls cancel() function
func (l LockContext) Cancel() {
	if l.cancel != nil {
		l.cancel()
	}
}

// newNSLock - return a new name space lock map.

    assertFailed(future, cause);
  }

  public void testCanceled() throws Exception {
    assertThat(future.cancel(false /* mayInterruptIfRunning */)).isTrue();
    assertCancelled(future, false);
  }

  public void testInterrupted() throws Exception {
    assertThat(future.cancel(true /* mayInterruptIfRunning */)).isTrue();
    assertCancelled(future, true);
  }

    inputFuture.cancel(true); // argument is ignored
    assertThrows(CancellationException.class, () -> resultFuture.get());
  }

  public void testFutureGetThrowsCancellationIfOutputCancelled() throws Exception {
    inputFuture.set(SLOW_OUTPUT_VALID_INPUT_DATA);
    outputFuture.cancel(true); // argument is ignored

    inputFuture.cancel(true); // argument is ignored
    assertThrows(CancellationException.class, () -> resultFuture.get());
  }

  public void testFutureGetThrowsCancellationIfOutputCancelled() throws Exception {
    inputFuture.set(SLOW_OUTPUT_VALID_INPUT_DATA);
    outputFuture.cancel(true); // argument is ignored

   * write.
   *
   * 2. visibility of the writes to an afterDone() call triggered by cancel():
   *
   * Since these fields are non-final that means that TimeoutFuture is not being 'safely published',
   * thus a motivated caller may be able to expose the reference to another thread that would then
   * call cancel() and be unable to cancel the delegate.

    async.setFuture(inner);
    async.cancel(false);
    assertTrue(inner.isCancelled());
    assertFalse(inner.wasInterrupted());
    assertThrows(CancellationException.class, inner::get);
  }

  public void testCancel_beforeSet() throws Exception {
    SettableFuture<Object> async = SettableFuture.create();
    async.cancel(true);
    assertFalse(async.set(42));
  }

			}
		}
	}
}

func (dm *DRWMutex) startContinuousLockRefresh(lockLossCallback func(), id, source string, quorum int) {
	ctx, cancel := context.WithCancel(context.Background())

	dm.m.Lock()
	dm.cancelRefresh = cancel
	dm.m.Unlock()

	go func() {
		defer cancel()

		refreshTimer := time.NewTimer(dm.refreshInterval)
		defer refreshTimer.Stop()

		for {
			select {
			case <-ctx.Done():