code: func GetRegionCodeForNumber(number *PhoneNumber) string {
  	var countryCode int = int(number.GetCountryCode())
  	var regions []string = CountryCodeToRegion[countryCode]
  	if len(regions) == 0 {
  		return ""
  	}
  	if len(regions) == 1 {
  		return regions[0]
  	}
  	return getRegionCodeForNumberFromRegionList(number, regions)
  }
docs: // Returns the region where a phone number is from. This could be used for
  // geocoding at the region level.