code: @Override
      public DescribePlacementGroupsResult describePlacementGroups(DescribePlacementGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeDescribePlacementGroups(request);
      }
docs: <p>
  Describes the specified placement groups or all of your placement groups. For more information, see <a
  href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html">Placement Groups</a> in the
  <i>Amazon Elastic Compute Cloud User Guide</i>.
  </p>
  
  @param describePlacementGroupsRequest
  @return Result of the DescribePlacementGroups operation returned by the service.
  @sample AmazonEC2.DescribePlacementGroups
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/ec2-2016-11-15/DescribePlacementGroups" target="_top">AWS
  API Documentation</a>