code: func NewRootedCamliFileSystem(cli *client.Client, fetcher blob.Fetcher, root blob.Ref) (*CamliFileSystem, error) {
  	fs := newCamliFileSystem(fetcher)
  	fs.client = cli
  
  	n, err := fs.newNodeFromBlobRef(root)
  
  	if err != nil {
  		return nil, err
  	}
  
  	fs.root = n
  
  	return fs, nil
  }
docs: // NewRootedCamliFileSystem returns a CamliFileSystem with a node based on a blobref
  // as its base.