Revert changes to ledger (uncommitted) and state made by any requests
        that have not been ordered.

def revert_unordered_batches(self):
        """
        Revert changes to ledger (uncommitted) and state made by any requests
        that have not been ordered.
        """
        i = 0
        for key in sorted(self.batches.keys(), reverse=True):
            if compare_3PC_keys(self.last_ordered_3pc, key) > 0:
                ledger_id, discarded, _, prevStateRoot, len_reqIdr = self.batches.pop(key)
                discarded = invalid_index_serializer.deserialize(discarded)
                self.logger.debug('{} reverting 3PC key {}'.format(self, key))
                self.revert(ledger_id, prevStateRoot, len_reqIdr - len(discarded))
                i += 1
            else:
                break
        return i