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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _format_option_strings(self, option, mvarfmt=' <%s>', optsep=', '):
 """ Return a comma-separated list of option strings and metavars. :param option: tuple of (short opt, long opt), e.g: ('-f', '--format') :param mvarfmt: metavar format string - evaluated as mvarfmt % metavar :param optsep: separator """

        opts = []

        if option._short_opts:
            opts.append(option._short_opts[0])
        if option._long_opts:
            opts.append(option._long_opts[0])
        if len(opts) > 1:
            opts.insert(1, optsep)

        if option.takes_value():
            metavar = option.metavar or option.dest.lower()
            opts.append(mvarfmt % metavar.lower())

        return ''.join(opts)