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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 update_default_rules(self):
 """Concatinate application and global security group rules."""

        app_ingress = self.properties['security_group']['ingress']
        ingress = conservative_merger.merge(DEFAULT_SECURITYGROUP_RULES, app_ingress)
        resolved_ingress = self.resolve_self_references(ingress)
        self.log.info('Updated default rules:\n%s', ingress)
        return resolved_ingress