private static HttpResponseMessage PostRequest(string json, string url)
        {
            Task<HttpResponseMessage> task = Task.Run(async () => await PostRequestAsync(json, url));
            task.Wait();
            return task.Result;
        }

        private static async Task<HttpResponseMessage> PostRequestAsync(string json, string url)
        {
            try
            {
                HttpResponseMessage response = await client.PostAsync(url, new StringContent(json, Encoding.UTF8, "application/json"));
                return response;
            }
            catch (HttpRequestException exc)
            {
                ThreadKill();
                Console.WriteLine(exc.InnerException.Message);
                Console.WriteLine("Press enter to exit...");
                Console.ReadLine();
                Environment.Exit(1);
                return new HttpResponseMessage();
            }
        }