code: def create_firewall_rule(self, server, firewall_rule_body):
          
          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'])
docs: 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.