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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 clear_all(self):
 """ Deletes all ``sandsnake`` related data from redis. .. warning:: Very expensive and destructive operation. Use with causion """

        keys = self._analytics_backend.keys()

        for key in itertools.chain(*keys):
            with self._analytics_backend.map() as conn:
                if key.startswith(self._prefix):
                    conn.delete(key)