code: func (s *FileStorage) Unlock(name string) error {
  	s.nameLocksMu.Lock()
  	defer s.nameLocksMu.Unlock()
  	wg, ok := s.nameLocks[name]
  	if !ok {
  		return fmt.Errorf("FileStorage: no lock to release for %s", name)
  	}
  	wg.Done()
  	delete(s.nameLocks, name)
  	return nil
  }
docs: // Unlock unlocks name.