private static void SaveStringToWaveFile(string text, string filePath, WatsonVoice voice, string key, string endpoint)
        {
            Text synthesizeText = new Text {
                _Text = text
            };
            TokenOptions options = new TokenOptions();

            options.IamApiKey = key;
            var _service = new SynthesizeWatsonVoice(options, endpoint);

            var synthesizeResult = _service.Synthesize(synthesizeText, "audio/wav", voice: "en-US_" + voice.VoiceName);

            StreamUtility.SaveStreamToFile(filePath, synthesizeResult);
        }
        public static void SaveStringToWaveFile(string text, string filePath, WatsonVoice voice)
        {
            if (!IsWatsonAccountPresentAndValid)
            {
                return;
            }
            string _key           = WatsonAccount.GetInstance().GetKey();
            string _endpoint      = EndpointToUriConverter.watsonRegionToEndpointMapping[WatsonAccount.GetInstance().GetRegion()];
            Text   synthesizeText = new Text {
                _Text = text
            };
            TokenOptions options = new TokenOptions();

            options.IamApiKey = _key;
            string endpoint = _endpoint;
            var    _service = new SynthesizeWatsonVoice(options, endpoint);

            var synthesizeResult = _service.Synthesize(synthesizeText, "audio/wav", voice: "en-US_" + voice.VoiceName);

            StreamUtility.SaveStreamToFile(filePath, synthesizeResult);
        }