code: def fileno(self) -> int:
      # for _MMapWrapper
      ...
  
imports: from __future__ import annotations
  from datetime import datetime, timedelta, tzinfo
  from os import PathLike
  from typing import TYPE_CHECKING, Any, Callable, Dict, Hashable, Iterator, List, Literal, Mapping, Optional, Protocol, Sequence, Tuple, Type, TypeVar, Union
  import numpy
label_desc: Use image node_id 2 for calling the ReadCsvBuffer obj's underlying member method code with example usage: obj.fileno() without return types