code: func waitOpenClipboard() error {
  	started := time.Now()
  	limit := started.Add(time.Second)
  	var r uintptr
  	var err error
  	for time.Now().Before(limit) {
  		r, _, err = openClipboard.Call(0)
  		if r != 0 {
  			return nil
  		}
  		time.Sleep(time.Millisecond)
  	}
  	return err
  }
docs: // waitOpenClipboard opens the clipboard, waiting for up to a second to do so.