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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_forever_values(self, forever_key):
 """ Delete all of the keys that have been stored forever. :type forever_key: str """

        forever = self._store.connection().lrange(forever_key, 0, -1)

        if len(forever) > 0:
            self._store.connection().delete(*forever)