code: func (p *Client) ClearSubscriptions() error {
  	p.Lock()
  	defer p.Unlock()
  	zero := make([]byte, 2)
  	for vh, s := range p.subs {
  		if err := p.ac.Write(s.cccdh, zero); err != nil {
  			return err
  		}
  		delete(p.subs, vh)
  	}
  	return nil
  }
docs: // ClearSubscriptions clears all subscriptions to notifications and indications.