code: def add_policy(self, scaling_group, name, policy_type, cooldown,
              change=None, is_percent=False, desired_capacity=None, args=None):
          
          uri = "/%s/%s/policies" % (self.uri_base, utils.get_id(scaling_group))
          body = self._create_policy_body(name, policy_type, cooldown,
                  change=change, is_percent=is_percent,
                  desired_capacity=desired_capacity, args=args)
          # "body" needs to be a list
          body = [body]
          resp, resp_body = self.api.method_post(uri, body=body)
          pol_info = resp_body.get("policies")[0]
          return AutoScalePolicy(self, pol_info, scaling_group)
docs: Adds a policy with the given values to the specified 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.