public void Update(BaseTransaction updatedTransaction)
 {
     BaseTransaction matches = transactionList.Where(t => t.TransactionID == updatedTransaction.TransactionID).First();
     if (matches != null)
     {
         transactionList.Remove(matches);
         transactionList.Add(updatedTransaction);
     }
 }
 public void Insert(BaseTransaction newTransaction)
 {
     transactionList.Add(newTransaction);
 }