code: func (w *Wallet) Unpair(pin []byte) error {
  	w.lock.Lock()
  	defer w.lock.Unlock()
  
  	if !w.session.paired() {
  		return fmt.Errorf("wallet %x not paired", w.PublicKey)
  	}
  	if err := w.session.verifyPin(pin); err != nil {
  		return fmt.Errorf("failed to verify pin: %s", err)
  	}
  	if err := w.session.unpair(); err != nil {
  		return fmt.Errorf("failed to unpair: %s", err)
  	}
  	if err := w.Hub.setPairing(w, nil); err != nil {
  		return err
  	}
  	return nil
  }
docs: // Unpair deletes an existing wallet pairing.