public Transaction ExecuteTransaction(Transaction transaction)
 {
     throw new NotImplementedException();
 }
 public Transaction ChargebackTransaction(Transaction transaction)
 {
     throw new NotImplementedException();
 }
 public Transaction CreateTransaction(Order order, TransactionType transactionType, BillingMethod billingMethod, double price, Transaction transactionReference = null)
 {
     throw new NotImplementedException();
 }
 public Transaction CancelTransaction(Transaction transaction)
 {
     throw new NotImplementedException();
 }