private void GetCustomVoiceModel()
        {
            if (string.IsNullOrEmpty(_customVoiceModelID))
            {
                throw new ArgumentNullException("customVoiceModelID");
            }

            Console.WriteLine(string.Format("Calling GetCustomVoiceModel({0})...", _customVoiceModelID));

            var results = _textToSpeech.GetCustomVoiceModel(_customVoiceModelID);

            if (results != null)
            {
                Console.WriteLine(string.Format("Name: {0} | Id: {1} | Language: {2} | Description: {3}",
                                                results.Name,
                                                results.Id,
                                                results.Language,
                                                results.Description));
            }
            else
            {
                Console.WriteLine(string.Format("Failed to find custom voice model {0} ...", _customVoiceModelID));
            }
        }