UnityEngine.Purchasing.TransactionLog.HasRecordOf C# (CSharp) Method

        public bool HasRecordOf(string transactionID)
        {
            if (string.IsNullOrEmpty(transactionID) || string.IsNullOrEmpty(this.persistentDataPath))
            {
                return false;
            }
            return Directory.Exists(this.GetRecordPath(transactionID));
        }

        /// <summary>
        /// Checks the product's transaction ID for uniqueness
        /// against the transaction log and calls the Application's
        /// ProcessPurchase method if so.
        /// </summary>
        private void ProcessPurchaseIfNew(Product product)
        {
            if (useTransactionLog && m_TransactionLog.HasRecordOf(product.transactionID))
            {
                m_Store.FinishTransaction(product.definition, product.transactionID);
                return;
            }

            var p = new PurchaseEventArgs(product);

            // Applications may elect to delay confirmations of purchases,
            // such as when persisting purchase state asynchronously.
            if (PurchaseProcessingResult.Complete == m_Listener.ProcessPurchase(p))
            {
                ConfirmPendingPurchase(product);
            }
        }