code: func (c *Cluster) AttachToContainer(opts docker.AttachToContainerOptions) error {
  	node, err := c.getNodeForContainer(opts.Container)
  	if err != nil {
  		return err
  	}
  	node.setPersistentClient()
  	return wrapError(node, node.AttachToContainer(opts))
  }
docs: // AttachToContainer attaches to a container, using the given options.