code: def __init__(self, file, backend):
      super().__init__(file)
      self.backend = backend
      self.devices_by_id = {d.id: d for d in backend.devices()}
  
file_path: jax/jax/experimental/serialize_executable.py
imports: from __future__ import annotations
  import pickle
  import io
  from typing import Optional, Union
  import jax
  from jax._src.lib import xla_client
label_desc: Use image node_id 1 to create a new _JaxPjrtUnpickler object from inherited base classes: pickle with example: obj = _JaxPjrtUnpickler(file, backend)