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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 _options_string(self):
 """ Return the option string. """

        if len(self.options) > 0:
            s = ""
            for op in self.options:
                if self._sized_op:
                    s += "{:s}={:s} ".format(*map(str, op))
                else:
                    s += "{:s} ".format(str(op))
            return s.strip()
        else:
            return ""