@SdkInternalApi
    final DeleteDBSubnetGroupResult executeDeleteDBSubnetGroup(DeleteDBSubnetGroupRequest deleteDBSubnetGroupRequest) {

        ExecutionContext executionContext = createExecutionContext(deleteDBSubnetGroupRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<DeleteDBSubnetGroupRequest> request = null;
        Response<DeleteDBSubnetGroupResult> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new DeleteDBSubnetGroupRequestMarshaller().marshall(super.beforeMarshalling(deleteDBSubnetGroupRequest));
                // 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, "DeleteDBSubnetGroup");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

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

            StaxResponseHandler<DeleteDBSubnetGroupResult> responseHandler = new StaxResponseHandler<DeleteDBSubnetGroupResult>(
                    new DeleteDBSubnetGroupResultStaxUnmarshaller());

            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Deletes a DB subnet group.
</p>
<note>
<p>
The specified database subnet group must not be associated with any DB instances.
</p>
</note>

@param deleteDBSubnetGroupRequest
@return Result of the DeleteDBSubnetGroup operation returned by the service.
@throws InvalidDBSubnetGroupStateException
        The DB subnet group cannot be deleted because it's in use.
@throws InvalidDBSubnetStateException
        The DB subnet isn't in the <i>available</i> state.
@throws DBSubnetGroupNotFoundException
        <code>DBSubnetGroupName</code> doesn't refer to an existing DB subnet group.
@sample AmazonRDS.DeleteDBSubnetGroup
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/rds-2014-10-31/DeleteDBSubnetGroup" target="_top">AWS API
     Documentation</a>
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/AmazonRDSClient.java