code: def __call__(self, global_step, backbone, partial_fc, backbone_onnx):
      if global_step > 100 and self.rank is 0:
          path_module = os.path.join(self.output, "backbone.pth")
          path_onnx = os.path.join(self.output, "backbone.onnx")
          torch.save(backbone.module.state_dict(), path_module)
          logging.info(
              "Pytorch Model Saved in '{}'".format(path_module)
          )
          convert_onnx(backbone_onnx, path_module, path_onnx)
          logging.info("Onnx Model Saved in '{}'".format(path_onnx))
  
      if global_step > 100 and partial_fc is not None:
          partial_fc.save_params()
  
imports: import logging
  import os
  import time
  from typing import List
  import torch
  from eval import verification
  from torch2onnx import convert_onnx
  from utils.utils_logging import AverageMeter
label_desc: Use image node_id 2 for calling the CallBackModelCheckpoint obj's underlying member method code with example usage: obj.__call__(global_step, backbone, partial_fc, backbone_onnx) without return types