code: def __enter__(self) -> Self:
      self._ref_count += 1
      if self._ref_count == 1:
          super().__enter__()
      return self
  
file_path: pyro/pyro/poutine/reentrant_messenger.py
imports: import functools
  from types import TracebackType
  from typing import Callable, Optional, Type, TypeVar
  from typing_extensions import ParamSpec, Self
  from pyro.poutine.messenger import Messenger
label_desc: Use image node_id 3 for calling the ReentrantMessenger obj's underlying member method code with example usage: obj.__enter__() and returns: self