@SdkInternalApi
    final CreateDefaultSubnetResult executeCreateDefaultSubnet(CreateDefaultSubnetRequest createDefaultSubnetRequest) {

        ExecutionContext executionContext = createExecutionContext(createDefaultSubnetRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<CreateDefaultSubnetRequest> request = null;
        Response<CreateDefaultSubnetResult> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new CreateDefaultSubnetRequestMarshaller().marshall(super.beforeMarshalling(createDefaultSubnetRequest));
                // 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, "EC2");
                request.addHandlerContext(HandlerContextKey.OPERATION_NAME, "CreateDefaultSubnet");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

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

            StaxResponseHandler<CreateDefaultSubnetResult> responseHandler = new StaxResponseHandler<CreateDefaultSubnetResult>(
                    new CreateDefaultSubnetResultStaxUnmarshaller());

            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Creates a default subnet with a size <code>/20</code> IPv4 CIDR block in the specified Availability Zone in your
default VPC. You can have only one default subnet per Availability Zone. For more information, see <a
href="https://docs.aws.amazon.com/vpc/latest/userguide/default-vpc.html#create-default-subnet">Create a default
subnet</a> in the <i>Amazon VPC User Guide</i>.
</p>

@param createDefaultSubnetRequest
@return Result of the CreateDefaultSubnet operation returned by the service.
@sample AmazonEC2.CreateDefaultSubnet
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/ec2-2016-11-15/CreateDefaultSubnet" target="_top">AWS API
     Documentation</a>
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/AmazonEC2Client.java