code: func (pn PhoneNumber) Local() string {
  	num, err := libphonenumber.Parse(string(pn), "US")
  	if err != nil {
  		return string(pn)
  	}
  	return libphonenumber.Format(num, libphonenumber.NATIONAL)
  }
docs: // Local returns a friendly national representation of the phone number, for
  // example, "+14105554092" is returned as "(410) 555-4092". If the phone number
  // is not in E.164 format, we try to parse it as a US number. If we cannot
  // parse it as a US number, it is returned as is.