public static async Task<bool> SignIn(string userName, string password)
        {
            var user = new { UserName = userName, Password = password };
           // HttpResponseMessage response = await CallAPI(client => client.PostAsJsonAsync("api/account/SignIn", user));
            HttpResponseMessage response = await CallAPI(client => client.PostAsync("api/AgentCollection", new StringContent(new JavaScriptSerializer().Serialize(user), Encoding.UTF8, "application/json")));


            bool result = false;
            if (response.IsSuccessStatusCode)
            {
                result = await response.Content.read.ReadAsAsync<bool>();
            }

            return result;
        }