code: func (imageState *ImageState) RemoveContainerReference(container *apicontainer.Container) error {
  	// Get the image state write lock for updating container reference
  	imageState.lock.Lock()
  	defer imageState.lock.Unlock()
  	for i := range imageState.Containers {
  		if imageState.Containers[i].Name == container.Name {
  			// Container reference found; hence remove it
  			seelog.Infof("Removing Container Reference: %v from Image State- %v", container.Name, imageState.Image.ImageID)
  			imageState.Containers = append(imageState.Containers[:i], imageState.Containers[i+1:]...)
  			// Update the last used time for the image
  			imageState.LastUsedAt = time.Now()
  			return nil
  		}
  	}
  	return fmt.Errorf("Container reference is not found in the image state container: %s", container.String())
  }
docs: // RemoveContainerReference removes container reference from image state