code: def _get_tpu_node_config():
      tpu_config_env = os.environ.get(_DEFAULT_TPUCONFIG_VARIABLE)
      if tpu_config_env:
          return json.loads(tpu_config_env)
      return None
  
imports: from concurrent import futures
  import datetime
  import json
  import logging
  import os
  import time
  import urllib
  from absl import flags
label_desc: Use image node_id 6 for calling a global function with example usage: _get_tpu_node_config() and returns: None, json