code: func (f *Fetcher) fetchImageDeps(hash string) error {
  	imgsl := list.New()
  	seen := map[string]dist.Distribution{}
  	f.addImageDeps(hash, imgsl, seen)
  	for el := imgsl.Front(); el != nil; el = el.Next() {
  		a := &asc{}
  		d := el.Value.(*dist.Appc)
  		str := d.String()
  		db := &distBundle{
  			dist:  d,
  			image: str,
  		}
  		hash, err := f.fetchSingleImage(db, a)
  		if err != nil {
  			return err
  		}
  		f.addImageDeps(hash, imgsl, seen)
  	}
  	return nil
  }
docs: // fetchImageDeps will recursively fetch all the image dependencies