code: def _read_init(self):
      self.shm = shm = SharedMemoryForRead(name=self._object_id)
      self._buffer = self._mv = shm.buf
      if self._size is None:
          (self._size,) = _qword_pack.unpack(shm.buf[-8:])
  
imports: import asyncio
  import os
  import random
  import struct
  import sys
  from string import ascii_letters, digits
  from typing import Any, Dict, List, Tuple, Optional
  from dataclasses import dataclass
  from ..serialization import AioSerializer, AioDeserializer
  from ..utils import implements, dataslots
  from .base import StorageBackend, StorageLevel, ObjectInfo, register_storage_backend
  from .core import BufferWrappedFileObject, StorageFileObject
label_desc: Use image node_id 4 for calling the SharedMemoryFileObject obj's underlying member method code with example usage: obj._read_init() without return types