class_docstr: Swiss army knife of broadcasting amazingness:
  combines shape inference, independence annotation, and subsampling
code: def _process_message(self, msg: "Message") -> None:
      super()._process_message(msg)
      BroadcastMessenger._pyro_sample(msg)
  
file_path: pyro/pyro/poutine/plate_messenger.py
imports: from contextlib import contextmanager
  from typing import TYPE_CHECKING, Iterator, Optional
  from pyro.poutine.broadcast_messenger import BroadcastMessenger
  from pyro.poutine.messenger import Messenger, block_messengers
  from pyro.poutine.subsample_messenger import SubsampleMessenger
label_desc: Use image node_id 1 for calling the PlateMessenger obj's underlying member method code with example usage: obj._process_message(msg) without return types