code: def _glibc_version_string_confstr() -> Optional[str]:
      """
      Primary implementation of glibc_version_string using os.confstr.
      """
      # os.confstr is quite a bit faster than ctypes.DLL. It's also less likely
      # to be broken or missing. This strategy is used in the standard library
      # platform module.
      # https://github.com/python/cpython/blob/fcf1d003bf4f0100c/Lib/platform.py#L175-L183
      try:
          # Should be a string like "glibc 2.17".
          version_string: str = getattr(os, "confstr")(
              "CS_GNU_LIBC_VERSION"
          )
          assert version_string is not None
          _, version = version_string.rsplit()
      except (AssertionError, AttributeError, OSError, ValueError):
          # os.confstr() or CS_GNU_LIBC_VERSION not available (or a bad value)...
          return None
      return version
  
imports: import collections
  import contextlib
  import functools
  import os
  import re
  import sys
  import warnings
  from typing import Dict, Generator, Iterator, NamedTuple, Optional, Tuple
  from ._elffile import EIClass, EIData, ELFFile, EMachine
label_desc: Use image node_id 5 for calling a global function with example usage: _glibc_version_string_confstr() and returns: version, None