code: func (v *view) close() error {
  	v.mu.Lock()
  	defer v.mu.Unlock()
  
  	// Close all fragments.
  	for _, frag := range v.fragments {
  		if err := frag.Close(); err != nil {
  			return errors.Wrap(err, "closing fragment")
  		}
  	}
  	v.fragments = make(map[uint64]*fragment)
  
  	return nil
  }
docs: // close closes the view and its fragments.