code: func (r *Repository) Branches() (storer.ReferenceIter, error) {
  	refIter, err := r.Storer.IterReferences()
  	if err != nil {
  		return nil, err
  	}
  
  	return storer.NewReferenceFilteredIter(
  		func(r *plumbing.Reference) bool {
  			return r.Name().IsBranch()
  		}, refIter), nil
  }
docs: // Branches returns all the References that are Branches.