code: public ApiSuccessResponse completeConference(String id, CompleteConferenceData completeConferenceData) throws ApiException {
          ApiResponse<ApiSuccessResponse> resp = completeConferenceWithHttpInfo(id, completeConferenceData);
          return resp.getData();
      }
docs: Complete a conference
  Complete a previously initiated two-step conference identified by the provided IDs. Once completed, the two separate calls are brought together so that all three parties are participating in the same call.
  @param id The connection ID of the consult call (established). (required)
  @param completeConferenceData  (required)
  @return ApiSuccessResponse
  @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body