code: func (d *Daemon) CheckNodeReadyCount(c *check.C) (interface{}, check.CommentInterface) {
  	nodes := d.ListNodes(c)
  	var readyCount int
  	for _, node := range nodes {
  		if node.Status.State == swarm.NodeStateReady {
  			readyCount++
  		}
  	}
  	return readyCount, nil
  }
docs: // CheckNodeReadyCount returns the number of ready node on the swarm