public void GivenAnExpense(string amount, string budget)
        {
            var debitAmount = decimal.Parse(amount);

            var flux = new Flow(budget, DateTime.Now, debitAmount, FlowType.Debit, "description");
            service.Add(flux);
        }
 public void Add(Flow flux)
 {
     var budget = budgetRepository.Budgets.FirstOrDefault(x => x.Name == flux.Budget);
     if (budget != null)
     {
         budget.Add(flux);
     }
 }
 public void Add(Flow flow)
 {
     flows.Add(flow);
 }