@SdkInternalApi
    final DescribeRegionsResult executeDescribeRegions(DescribeRegionsRequest describeRegionsRequest) {

        ExecutionContext executionContext = createExecutionContext(describeRegionsRequest);
        AWSRequestMetrics awsRequestMetrics = executionContext.getAwsRequestMetrics();
        awsRequestMetrics.startEvent(Field.ClientExecuteTime);
        Request<DescribeRegionsRequest> request = null;
        Response<DescribeRegionsResult> response = null;

        try {
            awsRequestMetrics.startEvent(Field.RequestMarshallTime);
            try {
                request = new DescribeRegionsRequestMarshaller().marshall(super.beforeMarshalling(describeRegionsRequest));
                // 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, "DescribeRegions");
                request.addHandlerContext(HandlerContextKey.ADVANCED_CONFIG, advancedConfig);

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

            StaxResponseHandler<DescribeRegionsResult> responseHandler = new StaxResponseHandler<DescribeRegionsResult>(
                    new DescribeRegionsResultStaxUnmarshaller());

            response = invoke(request, responseHandler, executionContext);

            return response.getAwsResponse();

        } finally {

            endClientExecution(awsRequestMetrics, request, response);
        }
    }
<p>
Describes the Regions that are enabled for your account, or all Regions.
</p>
<p>
For a list of the Regions supported by Amazon EC2, see <a
href="https://docs.aws.amazon.com/ec2/latest/devguide/ec2-endpoints.html">Amazon EC2 service endpoints</a>.
</p>
<p>
For information about enabling and disabling Regions for your account, see <a
href="https://docs.aws.amazon.com/accounts/latest/reference/manage-acct-regions.html">Specify which Amazon Web
Services Regions your account can use</a> in the <i>Amazon Web Services Account Management Reference Guide</i>.
</p>
<note>
<p>
The order of the elements in the response, including those within nested structures, might vary. Applications
should not assume the elements appear in a particular order.
</p>
</note>

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