code: def _glibc_version_string_confstr():
      # type: () -> 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/fcf1d003bf4f0100c9d0921ff3d70e1127ca1b71/Lib/platform.py#L175-L183
      try:
          # os.confstr("CS_GNU_LIBC_VERSION") returns a string like "glibc 2.17".
          version_string = os.confstr(  # type: ignore[attr-defined] # noqa: F821
              "CS_GNU_LIBC_VERSION"
          )
          assert version_string is not None
          _, version = version_string.split()  # type: Tuple[str, str]
      except (AssertionError, AttributeError, OSError, ValueError):
          # os.confstr() or CS_GNU_LIBC_VERSION not available (or a bad value)...
          return None
      return version
  
imports: from __future__ import absolute_import
  import distutils.util
  import collections
  import logging
  import os
  import platform
  import re
  import struct
  import sys
  import sysconfig
  import warnings
  from ._typing import TYPE_CHECKING, cast
label_desc: Use image node_id 17 for calling a global function with example usage: _glibc_version_string_confstr() and returns: version, None