code: func NewACName(s string) (*ACName, error) {
  	n := ACName(s)
  	if err := n.assertValid(); err != nil {
  		return nil, err
  	}
  	return &n, nil
  }
docs: // NewACName generates a new ACName from a string. If the given string is
  // not a valid ACName, nil and an error are returned.