code: func (d *KVKeysQuery) Fetch(clients *ClientSet, opts *QueryOptions) (interface{}, *ResponseMetadata, error) {
  	select {
  	case <-d.stopCh:
  		return nil, nil, ErrStopped
  	default:
  	}
  
  	opts = opts.Merge(&QueryOptions{
  		Datacenter: d.dc,
  	})
  
  	log.Printf("[TRACE] %s: GET %s", d, &url.URL{
  		Path:     "/v1/kv/" + d.prefix,
  		RawQuery: opts.String(),
  	})
  
  	list, qm, err := clients.Consul().KV().Keys(d.prefix, "", opts.ToConsulOpts())
  	if err != nil {
  		return nil, nil, errors.Wrap(err, d.String())
  	}
  
  	keys := make([]string, len(list))
  	for i, v := range list {
  		v = strings.TrimPrefix(v, d.prefix)
  		v = strings.TrimLeft(v, "/")
  		keys[i] = v
  	}
  
  	log.Printf("[TRACE] %s: returned %d results", d, len(list))
  
  	rm := &ResponseMetadata{
  		LastIndex:   qm.LastIndex,
  		LastContact: qm.LastContact,
  	}
  
  	return keys, rm, nil
  }
docs: // Fetch queries the Consul API defined by the given client.