code: func (kz *Kazoo) createOrUpdate(node string, value []byte, ephemeral bool) (err error) {
  	if _, err = kz.conn.Set(node, value, -1); err == nil {
  		return
  	}
  
  	if err == zk.ErrNoNode {
  		err = kz.create(node, value, ephemeral)
  	}
  	return
  }
docs: // createOrUpdate first attempts to update a node. If the nodes does not exist it will create it.