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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 create_firewall_rule(self, server, firewall_rule_body):
 """ Create a new firewall rule for a given server uuid. The rule can begiven as a dict or with FirewallRule.prepare_post_body(). Returns a FirewallRule object. """

        server_uuid, server_instance = uuid_and_instance(server)

        url = '/server/{0}/firewall_rule'.format(server_uuid)
        body = {'firewall_rule': firewall_rule_body}
        res = self.post_request(url, body)

        return FirewallRule(server=server_instance, **res['firewall_rule'])