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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 _rollback(self):
 """Restore the index in its previous state This uses values that were indexed/deindexed since the last call to `_reset_cache`. This is used when an error is encountered while updating a value, to return to the previous state """


        # to avoid using self set that may be updated during the process
        indexed_values = set(self._indexed_values)
        deindexed_values = set(self._deindexed_values)

        for args in indexed_values:
            self.remove(*args)
        for args in deindexed_values:
            self.add(*args, check_uniqueness=False)