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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 get_firewall_rule(self, server_uuid, firewall_rule_position, server_instance=None):
 """ Return a FirewallRule object based on server uuid and rule position. """

        url = '/server/{0}/firewall_rule/{1}'.format(server_uuid, firewall_rule_position)
        res = self.get_request(url)
        return FirewallRule(**res['firewall_rule'])