code: @Override
      public DescribePatchGroupsResult describePatchGroups(DescribePatchGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribePatchGroups(request);
      }
docs: <p>
  Lists all patch groups that have been registered with patch baselines.
  </p>
  
  @param describePatchGroupsRequest
  @return Result of the DescribePatchGroups operation returned by the service.
  @throws InternalServerErrorException
  An error occurred on the server side.
  @sample AWSSimpleSystemsManagement.DescribePatchGroups
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ssm-2014-11-06/DescribePatchGroups" target="_top">AWS API
  Documentation</a>