code: def shutil_which(pgm):
      """Python 2 compatibility: backport of ``shutil.which()`` from Python 3"""
      path = os.getenv("PATH")
      for p in path.split(os.path.pathsep):
          p = os.path.join(p, pgm)
          if os.path.exists(p) and os.access(p, os.X_OK):
              return p
  
file_path: speech_recognition/speech_recognition/audio.py
imports: import aifc
  import audioop
  import io
  import os
  import platform
  import stat
  import subprocess
  import sys
  import wave
label_desc: Use image node_id 2 for calling a global function with example usage: shutil_which(pgm) and returns: p