phonenumbers.go
func (n *NumberPurchasingService) Create(ctx context.Context, data url.Values) (*IncomingPhoneNumber, error) {
	number := new(IncomingPhoneNumber)
	pathPart := numbersPathPart
	if n.pathPart != "" {
		pathPart += "/" + n.pathPart
	}
	err := n.client.CreateResource(ctx, pathPart, data, number)
	return number, err
}
func (n *NumberPurchasingService) Create(ctx context.Context, data url.Values) (*IncomingPhoneNumber, error) {
	number := new(IncomingPhoneNumber)
	pathPart := numbersPathPart
	if n.pathPart != "" {
		pathPart += "/" + n.pathPart
	}
	err := n.client.CreateResource(ctx, pathPart, data, number)
	return number, err
}
// Create a phone number (buy a number) with the given values.
//
// https://www.twilio.com/docs/api/rest/incoming-phone-numbers#toll-free-incomingphonenumber-factory-resource