public void ProcessContract(Contract contract, int months)
 {
   double baseAmount = contract.TotalValue / months;
   for (int quota = 1; quota <= months; quota++)
   {
     DateTime dueDate = contract.Date.AddMonths(quota);
     double amount = _paymentService.Payment(baseAmount, quota);
     contract.AddPayment(new Payment(dueDate, amount));
   }
 }