code: func OpenReader(r io.Reader) error {
  	f, err := ioutil.TempFile("", "browser")
  	if err != nil {
  		return fmt.Errorf("browser: could not create temporary file: %v", err)
  	}
  	if _, err := io.Copy(f, r); err != nil {
  		f.Close()
  		return fmt.Errorf("browser: caching temporary file failed: %v", err)
  	}
  	if err := f.Close(); err != nil {
  		return fmt.Errorf("browser: caching temporary file failed: %v", err)
  	}
  	oldname := f.Name()
  	newname := oldname + ".html"
  	if err := os.Rename(oldname, newname); err != nil {
  		return fmt.Errorf("browser: renaming temporary file failed: %v", err)
  	}
  	return OpenFile(newname)
  }
docs: // OpenReader consumes the contents of r and presents the
  // results in a new browser window.