private final int timeoutMs;
    private CountdownTimer timer;

    public static ExponentialBackoff<Signal> of(int amount, TimeUnit unit) {
        return of(amount, unit, Signal.SLEEP);
    }

    public static <T extends Signal> ExponentialBackoff<T> of(int amount, TimeUnit unit, T signal) {
        return new ExponentialBackoff<T>((int) TimeUnit.MILLISECONDS.convert(amount, unit), signal, SLOT_TIME);
    }

                    return ExponentialBackoff.Result.successful(lockOutcome);
                } else {
                    return ExponentialBackoff.Result.notSuccessful(lockOutcome);
                }
            });
        }
    }

    private ExponentialBackoff<AwaitableFileLockReleasedSignal> newExponentialBackoff(int shortTimeoutMs) {

        try {
            ExponentialBackoff<ExponentialBackoff.Signal> backoff = ExponentialBackoff.of(5, TimeUnit.SECONDS, 50, TimeUnit.MILLISECONDS);
            backoff.retryUntil(() -> {
                URI baseUri = serversLeft.poll();
                if (baseUri == null) {
                    // no more servers left despite retries
                    return ExponentialBackoff.Result.successful(false);
                }

					}
				}
			}
		}
	}
}

// ignore nestedpendingoperations.IsAlreadyExists and exponentialbackoff.IsExponentialBackoff errors, they are expected.
func isExpectedError(err error) bool {
	return nestedpendingoperations.IsAlreadyExists(err) || exponentialbackoff.IsExponentialBackoff(err) || operationexecutor.IsMountFailedPreconditionError(err)

	}
	return nil
}

func (nim *nodeInfoManager) updateNode(updateFuncs ...nodeUpdateFunc) error {
	var updateErrs []error
	err := wait.ExponentialBackoff(updateBackoff, func() (bool, error) {
		if err := nim.tryUpdateNode(updateFuncs...); err != nil {
			updateErrs = append(updateErrs, err)
			return false, nil
		}
		return true, nil
	})
	if err != nil {

				rc.actualStateOfWorld.AddVolumeToReportAsAttached(logger, attachedVolume.VolumeName, attachedVolume.NodeName)

				if !exponentialbackoff.IsExponentialBackoff(err) {
					// Ignore exponentialbackoff.IsExponentialBackoff errors, they are expected.
					// Log all other errors.

	backoff := wait.Backoff{
		Duration: initialDuration,
		Factor:   3,
		Jitter:   0,
		Steps:    6,
	}
	return wait.ExponentialBackoff(backoff, fn)
}

func TestPluginRegistration(t *testing.T) {
	defer cleanup(t)

	pluginManager := newTestPluginManager(socketDir)

	// Start the plugin manager
	stopChan := make(chan struct{})

	// exits immediately
	i := 0
	err := ExponentialBackoff(Backoff{Factor: 1.0}, func() (bool, error) {
		i++
		return false, nil
	})
	if err != ErrWaitTimeout || i != 0 {
		t.Errorf("unexpected error: %v", err)
	}

	opts := Backoff{Factor: 1.0, Steps: 3}

	// waits up to steps
	i = 0
	err = ExponentialBackoff(opts, func() (bool, error) {
		i++
		return false, nil
	})

	backoff := wait.Backoff{
		Duration: initialDuration,
		Factor:   3,
		Jitter:   0,
		Steps:    6,
	}
	return wait.ExponentialBackoff(backoff, fn)
}

type DummyImpl struct{}

func NewDummyImpl() *DummyImpl {
	return &DummyImpl{}
}

// ValidatePlugin is a dummy implementation

		// after max retry steps.
		initBackoff := wait.Backoff{
			Steps:    6,
			Duration: 15 * time.Millisecond,
			Factor:   6.0,
			Jitter:   0.1,
		}
		err = wait.ExponentialBackoff(initBackoff, func() (bool, error) {
			klog.V(4).Infof("Initializing migrated drivers on CSINode")
			err := nim.InitializeCSINodeWithAnnotation()
			if err != nil {