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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 set(self, data, path=KISSmetrics.SET_PATH, resp=False):
 """Set a properties provided in `data` for identity. :param data: key-value pairs to associate with identity :type data: dict :param path: endpoint path; defaults to ``KISSmetrics.SET_PATH`` :param resp: indicate whether to return response :type resp: boolean :returns: an HTTP response for request if `resp=True` :rtype: `urllib3.response.HTTPResponse` :raises: Exception if either `identity` or `key` not set """

        self.check_id_key()
        timestamp = None
        response = self.client.set(person=self.identity, properties=data,
                                   timestamp=timestamp, path=path)
        if resp:
            return response