code: func (s *ShallowStorage) Shallow() ([]plumbing.Hash, error) {
  	f, err := s.dir.Shallow()
  	if f == nil || err != nil {
  		return nil, err
  	}
  
  	defer ioutil.CheckClose(f, &err)
  
  	var hash []plumbing.Hash
  
  	scn := bufio.NewScanner(f)
  	for scn.Scan() {
  		hash = append(hash, plumbing.NewHash(scn.Text()))
  	}
  
  	return hash, scn.Err()
  }
docs: // Shallow return the shallow commits reading from shallo file from .git