code: def handle_cd_command(arg):
      
      CD_CMD = 'cd'
      tokens = arg.split(CD_CMD + ' ')
      directory = tokens[-1] if len(tokens) > 1 else None
      if not directory:
          return False, "No folder name was provided."
      try:
          os.chdir(directory)
          subprocess.call(['pwd'])
          return True, None
      except OSError as e:
          return False, e.strerror
docs: Handles a `cd` shell command by calling python's os.chdir.