code: def _write_stub_file(
      self, stub_file: str, ext: Extension, compile=False
  ):
      log.info(
          "writing stub loader for %s to %s", ext._full_name, stub_file
      )
      if compile and os.path.exists(stub_file):
          raise BaseError(stub_file + " already exists! Please delete.")
      if not self.dry_run:
          f = open(stub_file, "w")
          f.write(
              "\n".join(
                  [
                      "def __bootstrap__():",
                      "   global __bootstrap__, __file__, __loader__",
                      "   import sys, os, pkg_resources, importlib.util"
                      + if_dl(", dl"),
                      "   __file__ = pkg_resources.resource_filename"
                      "(__name__,%r)"
                      % os.path.basename(ext._file_name),
                      "   del __bootstrap__",
                      "   if '__loader__' in globals():",
                      "       del __loader__",
                      if_dl("   old_flags = sys.getdlopenflags()"),
                      "   old_dir = os.getcwd()",
                      "   try:",
                      "     os.chdir(os.path.dirname(__file__))",
                      if_dl("     sys.setdlopenflags(dl.RTLD_NOW)"),
                      "     spec = importlib.util.spec_from_file_location(",
                      "                __name__, __file__)",
                      "     mod = importlib.util.module_from_spec(spec)",
                      "     spec.loader.exec_module(mod)",
                      "   finally:",
                      if_dl("     sys.setdlopenflags(old_flags)"),
                      "     os.chdir(old_dir)",
                      "__bootstrap__()",
                      "",  # terminal \n
                  ]
              )
          )
          f.close()
      if compile:
          self._compile_and_remove_stub(stub_file)
  
imports: import os
  import sys
  import itertools
  from importlib.machinery import EXTENSION_SUFFIXES
  from importlib.util import cache_from_source
  from typing import Dict, Iterator, List, Tuple
  from pathlib import Path
  from distutils.command.build_ext import build_ext
  from distutils.ccompiler import new_compiler
  from distutils.sysconfig import customize_compiler, get_config_var
  from distutils import log
  from setuptools.errors import BaseError
  from setuptools.extension import Extension, Library
  from distutils.sysconfig import _config_vars
label_desc: Use image node_id 20 for calling the build_ext obj's underlying member method code with example usage: obj._write_stub_file(stub_file, ext, compile) without return types