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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 add_policy(self, name, policy_type, cooldown, change=None, is_percent=False, desired_capacity=None, args=None):
 """ Adds a policy with the given values to this scaling group. The 'change' parameter is treated as an absolute amount, unless 'is_percent' is True, in which case it is treated as a percentage. """

        return self.manager.add_policy(self, name, policy_type, cooldown,
                change=change, is_percent=is_percent,
                desired_capacity=desired_capacity, args=args)