Object result = calculationListener.calculate(
getBuyerId(), getShoppingCart(), getBuyerLanguage(), this);
if (result instanceof MerchantCalculationResults) {
MerchantCalculationResults results = (MerchantCalculationResults) result;
ObjectFactory factory = new ObjectFactory();
return factory.createMerchantCalculationResults(results);
} else if (result instanceof String) {
String stringResult = (String) result;
return stringResult;
} else {
throw new RuntimeException(