code: func (g *metadataGraph) node(path string) *metadataNode {
  	cur := g.root
  	if path != "" {
  		for _, elem := range strings.Split(path, "/") {
  			cur = cur.child(elem)
  		}
  	}
  	return cur
  }
docs: // node returns a node at the given path, constructing it if necessary.
  //
  // 'path' here has a form "a/b/c", relative to the absolute root ("").