code: @Override
      public DescribeRegionsResult describeRegions(DescribeRegionsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribeRegions(request);
      }
docs: <p>
  Describes the regions that are currently available to you.
  </p>
  <p>
  For a list of the regions supported by Amazon EC2, see <a
  href="https://docs.aws.amazon.com/general/latest/gr/rande.html#ec2_region">Regions and Endpoints</a>.
  </p>
  
  @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>