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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 stop(self, historics_id, reason=''):
 """ Stop an existing Historics query. Uses API documented at http://dev.datasift.com/docs/api/rest-api/endpoints/historicsstop :param historics_id: playback id of the job to stop :type historics_id: str :param reason: optional reason for stopping the job :type reason: str :return: dict of REST API output with headers attached :rtype: :class:`~datasift.request.DictResponse` :raises: :class:`~datasift.exceptions.DataSiftApiException`, :class:`requests.exceptions.HTTPError` """

        return self.request.post('stop', data=dict(id=historics_id, reason=reason))