code: func (lf *lockFile) Close() error {
  	lf.Lock()
  	defer lf.Unlock()
  	if lf.f == syscall.InvalidHandle {
  		return nil
  	}
  	err := syscall.CloseHandle(lf.f)
  	lf.f = syscall.InvalidHandle
  	return err
  }
docs: // Close implements the LockFile interface