// Next two EnsureImageExists should be blocked because maxParallelImagePulls is hit
	for i := 0; i < 2; i++ {
		wg.Add(1)
		go func() {
			_, _, err := puller.EnsureImageExists(ctx, pod, container, nil, nil, "")
			assert.Nil(t, err)
			wg.Done()
		}()
	}
	time.Sleep(1 * time.Second)
	fakeRuntime.AssertCallCounts("PullImage", 5)

	// Unblock two image pulls from runtime, and two EnsureImageExists can go through

// Implementations are expected to abstract the underlying runtimes.
// Implementations are expected to be thread safe.
type ImageManager interface {
	// EnsureImageExists ensures that image specified in `container` exists.
	EnsureImageExists(ctx context.Context, pod *v1.Pod, container *v1.Container, pullSecrets []v1.Secret, podSandboxConfig *runtimeapi.PodSandboxConfig, podRuntimeHandler string) (string, string, error)

	if ref != nil {
		m.recorder.Event(ref, eventtype, event, msg)
	} else {
		logFn(fmt.Sprint(prefix, " ", msg))
	}
}

// EnsureImageExists pulls the image for the specified pod and container, and returns
// (imageRef, error message, error).

			if err != nil {
				msg := fmt.Sprintf("Failed to lookup runtimeHandler for runtimeClassName %v", pod.Spec.RuntimeClassName)
				return msg, err
			}
		}
	}

	imageRef, msg, err := m.imagePuller.EnsureImageExists(ctx, pod, container, pullSecrets, podSandboxConfig, podRuntimeHandler)
	if err != nil {
		s, _ := grpcstatus.FromError(err)