code: func MustAbs(dir string) string {
  	absDir, err := filepath.Abs(dir)
  	if err != nil {
  		panic(fmt.Sprintf("Failed to get absolute path of a directory %q: %v\n", dir, err))
  	}
  	return filepath.Clean(absDir)
  }
docs: // MustAbs returns an absolute path. It works like filepath.Abs, but
  // panics if it fails.