/// <summary>
        /// Initializes a new instance of the <see cref="TranslatorServiceClient"/> class, using the specified Subscription key and the desired language.
        /// </summary>
        /// <param name="subscriptionKey">The subscription key for the Microsoft Translator Service on Azure
        /// </param>
        /// <param name="language">A string representing the supported language code to translate the text to. The code must be present in the list of codes returned from the method <see cref="GetLanguageCodesAsync"/>. If a null value is provided, the current system language is used.
        /// </param>
        /// <remarks>
        /// <para>You must register Microsoft Translator on https://portal.azure.com to obtain the Subscription key needed to use the service.</para>
        /// </remarks>
        /// <seealso cref="SubscriptionKey"/>
        /// <seealso cref="Language"/>
        public TranslatorServiceClient(string subscriptionKey, string language = null)
        {
            authToken = new AzureAuthToken(subscriptionKey);
            client    = new HttpClient {
                BaseAddress = new Uri(BaseUrl)
            };

            SubscriptionKey = subscriptionKey;
            Language        = language ?? CultureInfo.CurrentCulture.Name.ToLower();
        }
        /// <summary>
        /// Initializes a new instance of the <strong>TranslatorService</strong> class, using the specified Client ID and Client Secret and the desired language.
        /// </summary>
        /// <param name="subscriptionKey">The subscription key for the Microsoft Translator Service on Azure
        /// </param>
        /// <param name="language">A string representing the supported language code to speak the text in. The code must be present in the list of codes returned from the method <see cref="GetLanguagesAsync"/>.</param>
        /// <remarks>
        /// <para>You must register Microsoft Translator on https://portal.azure.com to obtain the Subscription key needed to use the service.</para>
        /// </remarks>
        /// <seealso cref="SubscriptionKey"/>
        /// <seealso cref="Language"/>
        public TranslatorServiceClient(string subscriptionKey, string language)
        {
            authToken = new AzureAuthToken(subscriptionKey);
            client    = new HttpClient {
                BaseAddress = new Uri(BASE_URL)
            };

            SubscriptionKey = subscriptionKey;
            Language        = language;
        }