public async Task GetOne()
        {
            if (!MainController.Instance.global_parameters.ContainsKey("id"))
            {
                Feedback += "Parameter 'id' not found\n";
                return;
            }
            try
            {
                string id = MainController.Instance.global_parameters["id"];
                string url = users_path + "/" + id;
                var response = await _client.GetAsync(url);
                response.EnsureSuccessStatusCode();

                var user = await response.Content.ReadAsAsync<User>();
                User = user;
                UserFound = true;
            }
            catch (Newtonsoft.Json.JsonException jEx)
            {
                Feedback += jEx.Message + "\n";
            }
            catch (HttpRequestException ex)
            {
                Feedback += ex.Message + "\n";
            }  
        }
 public UsersController(HttpClient client) {
     _client = client;
     _user = User.EmptyInstance;
     _userFound = false;
 }