code: @Override
      public ListThingGroupsResult listThingGroups(ListThingGroupsRequest request) {
          request = beforeClientExecution(request);
          return executeListThingGroups(request);
      }
docs: <p>
  List the thing groups in your account.
  </p>
  
  @param listThingGroupsRequest
  @return Result of the ListThingGroups operation returned by the service.
  @throws InvalidRequestException
  The request is not valid.
  @throws InternalFailureException
  An unexpected error has occurred.
  @throws ResourceNotFoundException
  The specified resource does not exist.
  @sample AWSIot.ListThingGroups