private void LoadAllUsers()
        {
            AllUsers.Clear();
            var users = _userRepository.GetAll();

            AllUsers.AddRange(users);
        }
 /// <summary>
 /// Initializes the state amd data of the view model instance.
 /// </summary>
 protected override void OnInitialize()
 {
     try
     {
         var userList = _userRepository.GetAllUsers();
         AllUsers.Add(string.Empty);//For any user
         if (null != userList && userList.Any())
         {
             var userNameList = userList.Select(u => u.Username);
             AllUsers.AddRange(userNameList);
             Username = string.Empty;//set the selected user to all.
         }
     }
     catch (Exception ex)
     {
         LogUtil.LogError("TransactionFilterViewModel", "OnInitialize", ex);
         _messagingService.ShowMessage(ErrorMessages.ERR_FAILED_TO_GET_USERS, DialogType.Error);
     }
 }