code: def decode_cli_arg(arg):
      
      if arg is None:
          raise ValueError('Argument cannot be None')
  
      if sys.version_info.major == 3:
          # already decoded
          return arg
  
      return arg.decode(sys.getfilesystemencoding())
docs: Turn a bytestring provided by `argparse` into unicode.
  
      :param arg: The bytestring to decode.
      :return: The argument as a unicode object.
      :raises ValueError: If arg is None.