private async Task <IDictionary <string, ulong> > GetTransactionFeesAsync(IAgentContext agentContext)
        {
            if (_transactionFees == null)
            {
                var feesRequest = await IndyPayments.BuildGetTxnFeesRequestAsync(agentContext.Wallet, null, TokenConfiguration.MethodName);

                var feesResponse = await IndyLedger.SubmitRequestAsync(await agentContext.Pool, feesRequest);

                var feesParsed = await IndyPayments.ParseGetTxnFeesResponseAsync(TokenConfiguration.MethodName, feesResponse);

                _transactionFees = feesParsed.ToObject <IDictionary <string, ulong> >();
            }
            return(_transactionFees);
        }