public async Task <KeyPhrasesResult> KeyPhrasesAsync(DocumentsInput documentsInput)
        {
            var response = await Client.PostAsJsonAsync("keyPhrases", documentsInput);

            if (response.IsSuccessStatusCode)
            {
                return(await response.Content.ReadAsAsync <KeyPhrasesResult>());
            }
            return(new KeyPhrasesResult());
        }
        public async Task <SentimentResult> SentimentAsync(DocumentsInput documentsInput)
        {
            var response = await Client.PostAsJsonAsync("sentiment", documentsInput);

            if (response.IsSuccessStatusCode)
            {
                return(await response.Content.ReadAsAsync <SentimentResult>());
            }

            return(new SentimentResult());
        }