code: func NewPricingClient(accountSid string, authToken string, httpClient *http.Client) *Client {
  	if httpClient == nil {
  		httpClient = &http.Client{Timeout: defaultTimeout}
  	}
  	restClient := rest.NewClient(accountSid, authToken, PricingBaseURL)
  	c := &Client{Client: restClient, AccountSid: accountSid, AuthToken: authToken}
  	c.APIVersion = PricingVersion
  	c.FullPath = func(pathPart string) string {
  		return "/" + c.APIVersion + "/" + pathPart
  	}
  	c.Voice = &VoicePriceService{
  		Countries: &CountryVoicePriceService{client: c},
  		Numbers:   &NumberVoicePriceService{client: c},
  	}
  	c.Messaging = &MessagingPriceService{
  		Countries: &CountryMessagingPriceService{client: c},
  	}
  	c.PhoneNumbers = &PhoneNumberPriceService{
  		Countries: &CountryPhoneNumberPriceService{client: c},
  	}
  	return c
  }
docs: // returns a new Client to use the pricing API