def set_short_opt_delimiter(self, delim):
        if ("", " ") not in delim:
            raise ValueError(
                "invalid metavar delimiter for short options: %r" % delim)
        self._short_opt_fmt = "%s" + delim + "%s"
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/optparse.py/HelpFormatter.set_short_opt_delimiter/swapped operands of `not in`