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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 delete_existing_policy(self, scaling_policy, server_group):
 """Given a scaling_policy and server_group, deletes the existing scaling_policy. Scaling policies need to be deleted instead of upserted for consistency. Args: scaling_policy (json):
 the scaling_policy json from Spinnaker that should be deleted server_group (str):
 the affected server_group """

        self.log.info("Deleting policy %s on %s", scaling_policy['policyName'], server_group)
        delete_dict = {
            "application":
            self.app,
            "description":
            "Delete scaling policy",
            "job": [{
                "policyName": scaling_policy['policyName'],
                "serverGroupName": server_group,
                "credentials": self.env,
                "region": self.region,
                "provider": "aws",
                "type": "deleteScalingPolicy",
                "user": "foremast-autoscaling-policy"
            }]
        }
        wait_for_task(json.dumps(delete_dict))