code: func (p *pin) EndWatch() error {
  
  	fd := int(p.valueFile.Fd())
  
  	if err := syscall.EpollCtl(epollFD, syscall.EPOLL_CTL_DEL, fd, nil); err != nil {
  		return err
  	}
  
  	if err := syscall.SetNonblock(fd, false); err != nil {
  		return err
  	}
  
  	delete(watchEventCallbacks, fd)
  
  	return nil
  
  }
docs: // EndWatch stops watching the pin