code: def run_test(self, test_config, r_tol):
      print("\n")
  
      print("{0}: starting......".format(self.id()))
  
      # Cache save and load gpu counts
      save_gpus = test_config["gpus"]
      if "load_gpus" in test_config:
          load_gpus = test_config["load_gpus"]
          del test_config["load_gpus"]
      else:
          load_gpus = test_config["gpus"]
  
      # save to current directory.
      checkpoint_folder = test_config["checkpoint_name"]
      checkpoint_interval = test_config["checkpoint_interval"]
      checkpoint_name = test_config["checkpoint_name"]
      # ---------------remove old checkpoint---------------#
      try:
          cmd = f"rm -rf {checkpoint_name}"
          print(f"{self.id()} cmd: {cmd}")
          subprocess.run(
              cmd, shell=True, check=False, executable="/bin/bash"
          )
      except:
          print("No old checkpoint")
  
      if (
          "cpu_optimizer" in test_config
          and test_config["cpu_optimizer"]
      ):
          cpu_optimizer_flag = " --cpu-optimizer"
      else:
          cpu_optimizer_flag = ""
  
      # -----------------Saving Checkpoint-----------------#
      # building checkpoint arguments
      test_config[
          "other_args"
      ] = f'"--save {checkpoint_folder} --save-interval {checkpoint_interval} {cpu_optimizer_flag}"'
  
      prefix = "gpt2_saving_checkpoint"
  
      # create checkpoint run...
      base_file = self.gen_name(test_config, prefix)
  
      # remove previous test log
      try:
          cmd = f"rm {base_file}"
          subprocess.run(
              cmd, shell=True, check=False, executable="/bin/bash"
          )
      except:
          print(f"{self.id()} No old logs")
  
      print("{0}: Run for saving checkpoint".format(self.id()))
      self.run_gpt2_test(test_config, base_file)
  
      # -----------------Loading Checkpoint-----------------#
  
      # building checkpoint arguments
      test_config[
          "other_args"
      ] = f'"--load {checkpoint_folder} {cpu_optimizer_flag} "'
  
      # set checkpoint load iteration
      try:
          cmd = f"echo {checkpoint_interval} > {checkpoint_name}/latest_checkpointed_iteration.txt"
          print(f"{self.id()} running cmd: {cmd}")
          subprocess.run(
              cmd, shell=True, check=False, executable="/bin/bash"
          )
      except:
          print(
              f"{self.id()} Failed to update the checkpoint iteration file"
          )
          return False
  
      prefix = "gpt2_loading_checkpoint"
  
      # set load gpus
      test_config["gpus"] = load_gpus
  
      print(
          "{0}: Second run loading checkpoint and continuing.".format(
              self.id()
          )
      )
      test_file = self.gen_name(test_config, prefix)
  
      # remove previous test log
      try:
          cmd = f"rm {test_file}"
          subprocess.run(
              cmd, shell=True, check=False, executable="/bin/bash"
          )
      except:
          print(f"{self.id()} no previous logs for")
      self.run_gpt2_test(test_config, test_file)
      return self.check_parity(base_file, test_file, r_tol)
  
imports: import unittest
  import subprocess
  import os
  import re
  from .test_common import BaseTestCase
label_desc: Use image node_id 21 for calling the GPT2CheckpointTestCase obj's underlying member method code with example usage: obj.run_test(test_config, r_tol) and returns: self, False