code: def is_extension_module(filename):
      """Return whether the given filename is an extension module.
  
      This simply checks that the extension is either .so or .pyd.
      """
      return os.path.splitext(filename)[1].lower() in (".so", ".pyd")
  
imports: import doctest
  import inspect
  import logging
  import os
  import re
  import sys
  from testpath import modified_env
  from inspect import getmodule
  from doctest import REPORTING_FLAGS, REPORT_ONLY_FIRST_FAILURE, _unittest_reportflags, DocTestRunner, _extract_future_flags, pdb, _OutputRedirectingPdb, _exception_traceback, linecache
  from nose.plugins import doctests, Plugin
  from nose.util import anyp, tolist
  from IPython.utils.py3compat import builtin_mod, PY3, getcwd
label_desc: Use image node_id 1 for calling a global function with example usage: is_extension_module(filename) and returns: unknown