code: func (imageManager *dockerImageManager) removeImageState(imageStateToBeRemoved *image.ImageState) {
  	for i, imageState := range imageManager.imageStates {
  		if imageState.Image.ImageID == imageStateToBeRemoved.Image.ImageID {
  			// Image State found; hence remove it
  			seelog.Infof("Removing Image State: [%s] from Image Manager", imageState.String())
  			imageManager.imageStates = append(imageManager.imageStates[:i], imageManager.imageStates[i+1:]...)
  			return
  		}
  	}
  }
docs: // removeImageState removes the imageState from the list of imageState objects in ImageManager