code: func (e *Engine) thisNode() (*seesaw.Node, error) {
  	e.clusterLock.RLock()
  	c := e.cluster
  	e.clusterLock.RUnlock()
  
  	if c == nil {
  		return nil, fmt.Errorf("cluster configuration not loaded")
  	}
  	// TODO(jsing): This does not allow for IPv6-only operation.
  	ip := e.config.Node.IPv4Addr
  	for _, n := range c.Nodes {
  		if ip.Equal(n.IPv4Addr) {
  			return n, nil
  		}
  	}
  	return nil, fmt.Errorf("node %v not configured", ip)
  }
docs: // thisNode returns the Node for the machine on which this engine is running.