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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 parse(cls, rule_string):
 """ returns a list of rules a single line may yield multiple rules """

        result = parser.parseString(rule_string)
        rules = []
        # breakout port ranges into multple rules

        kwargs = {}

        kwargs['address'] = result.ip_and_mask or None
        kwargs['group'] = result.security_group or None
        kwargs['group_name'] = result.group_name or None

        for x,y in result.ports:
            r = Rule(result.protocol, x, y, **kwargs)
            rules.append(r)
        return rules