code: func makeBasePath(base, relative string) string {
  	if !strings.HasSuffix(base, "/") && relative != "" {
  		base += "/"
  	}
  	return httprouter.CleanPath(base + relative)
  }
docs: // makeBasePath combines the given base and relative path using "/".
  // The result is: "/"+base+"/"+relative. Consecutive "/" are collapsed
  // into a single "/". In addition, the following rules apply:
  //         - The "/" between base and relative exists only if either base has a
  //           trailing "/" or relative is not the empty string.
  //         - A trailing "/" is added to the result if relative has a trailing
  //           "/".