class_docstr: Helper class for async checkpoint.
docstr: Expose the most recent error from the async saving thread to the caller.
      
docstr_tok: ["Expose","the","most","recent","error","from","the","async","saving","thread","to","the","caller","."]
code: def _check_async_thread_error(self):
      """Expose the most recent error from the async saving thread to the caller."""
      if self._async_error:
          e = self._async_error
          self._async_error = None
          logging.error(
              "Propagating the most recent error from the async thread "
              "before joining: %s",
              str(e),
          )
          raise e
  
imports: import atexit
  import copy
  import queue
  import threading
  import time
  import weakref
  from absl import logging
  from tensorflow.python.checkpoint import checkpoint_context
  from tensorflow.python.checkpoint import trackable_view
  from tensorflow.python.distribute import device_util
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.eager import executor
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import variables
  from tensorflow.python.saved_model.pywrap_saved_model import metrics
  from tensorflow.python.trackable import base
  from tensorflow.python.util import object_identity
label_desc: Use image node_id 5 for calling the AsyncCheckpointHelper obj's underlying member method code with example usage: obj._check_async_thread_error() without return types