How to use the sacrebleu._chrf function in sacrebleu

executor.submit(
                        sb.get_corpus_statistics, b[0], b[1][0]
                    )
                    for b in batches
                ]
                progress = as_completed(futures)
                if self.verbose:
                    progress = tqdm(progress)
                for future in progress:
                    stats = future.result()
                    for i in range(sb.CHRF_ORDER * 3):
                        corpus_statistics[i] += stats[i]
            avg_precision, avg_recall = sb._avg_precision_and_recall(
                corpus_statistics, sb.CHRF_ORDER
            )
            corpus_score = sb._chrf(avg_precision, avg_recall)
        return corpus_score