code: @Override
      public ListGroupVersionsResult listGroupVersions(ListGroupVersionsRequest request) {
          request = beforeClientExecution(request);
          return executeListGroupVersions(request);
      }
docs: Lists the versions of a group.
  
  @param listGroupVersionsRequest
  @return Result of the ListGroupVersions operation returned by the service.
  @throws BadRequestException
  invalid request
  @sample AWSGreengrass.ListGroupVersions
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/greengrass-2017-06-07/ListGroupVersions" target="_top">AWS
  API Documentation</a>