code: func ExtractWildcards(path string) []string {
  	matches := WildcardRegex.FindAllStringSubmatch(path, -1)
  	wcs := make([]string, len(matches))
  	for i, m := range matches {
  		wcs[i] = m[1]
  	}
  	return wcs
  }
docs: // ExtractWildcards returns the names of the wildcards that appear in path.