code: func cleanPath(p string) string {
  	if p == "" {
  		return "/"
  	}
  	if p[0] != '/' {
  		p = "/" + p
  	}
  	np := path.Clean(p)
  	// path.Clean removes trailing slash except for root;
  	// put the trailing slash back if necessary.
  	if p[len(p)-1] == '/' && np != "/" {
  		np += "/"
  	}
  	return np
  }
docs: // cleanPath returns the canonical path for p, eliminating . and .. elements.
  // Borrowed from the net/http package.