code: def replace_webhook(self, scaling_group, policy, webhook, name,
              metadata=None):
          
          uri = "/%s/%s/policies/%s/webhooks/%s" % (self.uri_base,
                  utils.get_id(scaling_group), utils.get_id(policy),
                  utils.get_id(webhook))
          group_id = utils.get_id(scaling_group)
          policy_id = utils.get_id(policy)
          webhook_id = utils.get_id(webhook)
          body = self._create_webhook_body(name, metadata=metadata)
          resp, resp_body = self.api.method_put(uri, body=body)
docs: Replace an existing webhook. All of the attributes must be specified.
          If you wish to delete any of the optional attributes, pass them in as
          None.