public async Task <IActionResult> OnPostAsync()
        {
            return(await ExpenseFlow.ProcessAsync(ModelState, nameof(ExpenseFlow),
                                                  async() =>
            {
                var model = new ExpenseFlowModel {
                    Id = -1
                };
                ExpenseFlow.ToExpenseFlowModel(model);
                await _expenseFlowCommands.Update(model);
                return RedirectToPage("./ExpenseFlows");
            },

                                                  async() => await Task.FromResult(Page())
                                                  ));
        }
        public async Task <IActionResult> OnPostCommitAsync()
        {
            return(await ExpenseFlow.ProcessAsync(ModelState, nameof(ExpenseFlow),
                                                  async() =>
            {
                var model = await _expenseFlowQueries.GetById(ExpenseFlow.Id);
                ExpenseFlow.ToExpenseFlowModel(model);
                await _expenseFlowCommands.Update(model);
                return RedirectToPage("./ExpenseFlows");
            },

                                                  async() =>
            {
                await LoadCategories();
                return Page();
            }));
        }