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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):
 """Rolls back the current transaction. This method has necessary side-effects: - Sets the current transaction's ID to None. """

        try:
            # No need to use the response it contains nothing.
            self._client._datastore_api.rollback(self.project, self._id)
        finally:
            super(Transaction, self).rollback()
            # Clear our own ID in case this gets accidentally reused.
            self._id = None