code: def accumulate(self):
      self._mpii_keypoint_results_save()
      if self.save_prediction_only:
          logger.info(
              f"The keypoint result is saved to {self.res_file} "
              "and do not evaluate the mAP."
          )
          return
  
      self.eval_results = self.evaluate(self.results)
  
imports: import os
  import json
  from collections import defaultdict, OrderedDict
  import numpy
  import paddle
  from pycocotools.coco import COCO
  from pycocotools.cocoeval import COCOeval
  from ..modeling.keypoint_utils import oks_nms, keypoint_pck_accuracy, keypoint_auc, keypoint_epe
  from scipy.io import loadmat, savemat
  from ppdet.utils.logger import setup_logger
label_desc: Use image node_id 4 for calling the KeyPointTopDownMPIIEval obj's underlying member method code with example usage: obj.accumulate() without return types