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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_event_subscription(self, url):
 """Deregister a callback URL as an event subscriber. :param str url: callback URL :returns: the deleted event subscription :rtype: dict """

        params = {'callbackUrl': url}
        response = self._do_request('DELETE', '/v2/eventSubscriptions', params)
        return response.json()