@SdkInternalApi
    final DescribeDBParameterGroupsResult executeDescribeDBParameterGroups(DescribeDBParameterGroupsRequest describeDBParameterGroupsRequest) {

        ExecutionContext executionContext = createExecutionContext(describeDBParameterGroupsRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<DescribeDBParameterGroupsRequest> request = null;
        Response<DescribeDBParameterGroupsResult> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new DescribeDBParameterGroupsRequestMarshaller().marshall(super.beforeMarshalling(describeDBParameterGroupsRequest));
                // 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, "DescribeDBParameterGroups");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

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

            StaxResponseHandler<DescribeDBParameterGroupsResult> responseHandler = new StaxResponseHandler<DescribeDBParameterGroupsResult>(
                    new DescribeDBParameterGroupsResultStaxUnmarshaller());

            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Returns a list of <code>DBParameterGroup</code> descriptions. If a <code>DBParameterGroupName</code> is
specified, the list will contain only the description of the specified DB parameter group.
</p>

@param describeDBParameterGroupsRequest
@return Result of the DescribeDBParameterGroups operation returned by the service.
@throws DBParameterGroupNotFoundException
        <code>DBParameterGroupName</code> doesn't refer to an existing DB parameter group.
@sample AmazonRDS.DescribeDBParameterGroups
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/DescribeDBParameterGroups" target="_top">AWS
     API Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java