@SdkInternalApi
    final ReservedDBInstance executePurchaseReservedDBInstancesOffering(PurchaseReservedDBInstancesOfferingRequest purchaseReservedDBInstancesOfferingRequest) {

        ExecutionContext executionContext = createExecutionContext(purchaseReservedDBInstancesOfferingRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<PurchaseReservedDBInstancesOfferingRequest> request = null;
        Response<ReservedDBInstance> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new PurchaseReservedDBInstancesOfferingRequestMarshaller().marshall(super
                        .beforeMarshalling(purchaseReservedDBInstancesOfferingRequest));
                // Binds the request metrics to the current request.
                request.setAWSRequestMetrics(awsRequestMetrics);
                request.addHandlerContext(HandlerContextKey.CLIENT_ENDPOINT, endpoint);
                request.addHandlerContext(HandlerContextKey.ENDPOINT_OVERRIDDEN, isEndpointOverridden());
                request.addHandlerContext(HandlerContextKey.SIGNING_REGION, getSigningRegion());
                request.addHandlerContext(HandlerContextKey.SERVICE_ID, "RDS");
                request.addHandlerContext(HandlerContextKey.OPERATION_NAME, "PurchaseReservedDBInstancesOffering");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

            } finally {
                awsRequestMetrics.endEvent(Field.RequestMarshallTime);
            }

            StaxResponseHandler<ReservedDBInstance> responseHandler = new StaxResponseHandler<ReservedDBInstance>(new ReservedDBInstanceStaxUnmarshaller());

            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Purchases a reserved DB instance offering.
</p>

@param purchaseReservedDBInstancesOfferingRequest
@return Result of the PurchaseReservedDBInstancesOffering operation returned by the service.
@throws ReservedDBInstancesOfferingNotFoundException
        Specified offering does not exist.
@throws ReservedDBInstanceAlreadyExistsException
        User already has a reservation with the given identifier.
@throws ReservedDBInstanceQuotaExceededException
        Request would exceed the user's DB Instance quota.
@sample AmazonRDS.PurchaseReservedDBInstancesOffering
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/PurchaseReservedDBInstancesOffering"
     target="_top">AWS API Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java