code: def __enter__(self) -> "_HeartbeatReporter":
      self.start()
      return self
  
imports: import atexit
  import logging
  import sys
  import threading
  import time
  import types
  from typing import Any, Optional, Union
  from determined.common import api
  from determined.common.api import bindings
label_desc: Use image node_id 5 for calling the _HeartbeatReporter obj's underlying member method code with example usage: obj.__enter__() and returns: self