code: func (s *VolumeStore) Release(ctx context.Context, name string, ref string) error {
  	s.locks.Lock(name)
  	defer s.locks.Unlock(name)
  	select {
  	case <-ctx.Done():
  		return ctx.Err()
  	default:
  	}
  
  	s.globalLock.Lock()
  	defer s.globalLock.Unlock()
  
  	select {
  	case <-ctx.Done():
  		return ctx.Err()
  	default:
  	}
  
  	if s.refs[name] != nil {
  		delete(s.refs[name], ref)
  	}
  	return nil
  }
docs: // Release releases the specified reference to the volume