Make Http request to FB to get access token

makeHttpRequest.cs

        public static async Task<string> GetFacebookProfileName(string accessToken)
        {
            var uri = GetUri("https://graph.facebook.com/v2.6/me",
                Tuple.Create("fields", "id,name"),
                Tuple.Create("access_token", accessToken));

            var res = await FacebookRequest<FacebookProfile>(uri);
            return res.Name;
        }
        
        private static async Task<T> FacebookRequest<T>(Uri uri)
        {
            string json;
            using (HttpClient client = new HttpClient())
            {
                json = await client.GetStringAsync(uri).ConfigureAwait(false);
            }

            try
            {
                var result = JsonConvert.DeserializeObject<T>(json);
                return result;
            }
            catch (JsonException ex)
            {
                throw new ArgumentException("Unable to deserialize the Facebook response.", ex);
            }
        }

        private static Uri GetUri(string endPoint, params Tuple<string, string>[] queryParams)
        {
            var queryString = HttpUtility.ParseQueryString(string.Empty);
            foreach (var queryparam in queryParams)
            {
                queryString[queryparam.Item1] = queryparam.Item2;
            }

            var builder = new UriBuilder(endPoint);
            builder.Query = queryString.ToString();
            return builder.Uri;
        }

        //if not support HttpUtility.ParseQueryString, below is an alternative way
        //https://stackoverflow.com/questions/27442985/alternative-to-httputility-parsequerystring-without-system-web-dependency
        //public static Uri GetUri(string endPoint, params Tuple<string, string>[] queryParams)
        //{
        //    var builder = new UriBuilder(endPoint);
        //    string paramUrl = string.Join("&", queryParams.Select(u => $"{WebUtility.UrlEncode(u.Item1)}={WebUtility.UrlEncode(u.Item2)}"));
        //    builder.Query = paramUrl;
        //    return builder.Uri;
        //}