code: func (g *Graph) Find(re string) (*Graph, error) {
  	exp, err := regexp.Compile(re)
  
  	if err != nil {
  		return nil, err
  	}
  
  	r := New("_")
  
  	for _, node := range g.Out {
  		if exp.MatchString(node.ThisString()) {
  			r.Add(node)
  		}
  	}
  
  	return r, nil
  }
docs: // Find returns a Graph with all subnodes that match the regular
  // expression given. It only walks through the subnodes of the current Graph.
  // If the regex doesn't compile, an error will be returned. If the result set
  // is empty, both return values are nil (no error is signaled).