protected abstract AbstractAccountPostProcessor GetAccountPostProcessor(IAccountNumberChecker accountNumberChecker);
 public CheckNumberValidityAccountPostProcessor(IAccountNumberChecker accountNumberChecker)
 {
     this.accountNumberChecker = accountNumberChecker;
 }
 protected override AbstractAccountPostProcessor GetAccountPostProcessor(IAccountNumberChecker accountNumberChecker)
 {
     return new CheckNumberValidityAccountPostProcessor(accountNumberChecker);
 }