private void appendPeriodicPurchaseInfo(StringBuilder req, PeriodicPurchaseInfo periodicPurchaseInfo)
 {
     if (periodicPurchaseInfo.getPerPaymentAmount() >= 0) {
         this.appendAmount(req,periodicPurchaseInfo.getPerPaymentAmount());
     }
     if (periodicPurchaseInfo.getState() != null) {
         this.appendPeriodicPurchaseState(req, periodicPurchaseInfo.getState());
     }
     if (periodicPurchaseInfo.getSchedule() != null) {
         this.appendPeriodicPurchaseSchedule(req, periodicPurchaseInfo.getSchedule());
     }
     if (periodicPurchaseInfo.getOrderId() != null) {
         this.appendOrderId(req, periodicPurchaseInfo.getOrderId());
     }
     if (periodicPurchaseInfo.getCustomerId() != null) {
         this.appendParam(req, "customerId", periodicPurchaseInfo.getCustomerId());
     }
     if (periodicPurchaseInfo.getStartDate() != DateTime.MinValue) {
         this.appendStartDate(req, periodicPurchaseInfo.getStartDate());
     }
     if (periodicPurchaseInfo.getEndDate() != DateTime.MinValue) {
         this.appendEndDate(req, periodicPurchaseInfo.getEndDate());
     }
     if (periodicPurchaseInfo.getNextPaymentDate() != DateTime.MinValue) {
         this.appendNextPaymentDate(req, periodicPurchaseInfo.getNextPaymentDate());
     }
     if (periodicPurchaseInfo.getExecutionType() != null)
     {
         this.appendParam(req, "periodicPurchaseExecutionType", periodicPurchaseInfo.getExecutionType());
     }
 }