private async void ExecuteLoadUserCommand()
        {
            //var _users = new List<User>
            //{
            //    new User{ FirstName = "Narendra", LastName = "Nalluri"},
            //    new User{ FirstName = "Pratap", LastName = "Pesaru"},
            //    new User{ FirstName = "Mani"}
            //};

            var _users = await _userService.GetUserList();

            Users.Clear();
            foreach (var user in _users)
            {
                Users.Add(user);
            }
        }