prices_voice.go
func (cvps *CountryVoicePriceService) GetPage(ctx context.Context, data url.Values) (*CountriesPricePage, error) {
	return cvps.GetPageIterator(data).Next(ctx)
}
func (cvps *CountryVoicePriceService) GetPage(ctx context.Context, data url.Values) (*CountriesPricePage, error) {
	return cvps.GetPageIterator(data).Next(ctx)
}
// returns a list of countries where Twilio voice services are available and the corresponding URL
// for retrieving the country specific voice prices.