code: func (i *Index) Add(path string) *Entry {
  	e := &Entry{
  		Name: filepath.ToSlash(path),
  	}
  
  	i.Entries = append(i.Entries, e)
  	return e
  }
docs: // Add creates a new Entry and returns it. The caller should first check that
  // another entry with the same path does not exist.