code: def delete_event_subscription(self, url):
          
          params = {'callbackUrl': url}
          response = self._do_request('DELETE', '/v2/eventSubscriptions', params)
          return response.json()
docs: Deregister a callback URL as an event subscriber.
  
          :param str url: callback URL
  
          :returns: the deleted event subscription
          :rtype: dict