code: def rouge_2(hypotheses, references):
      
      rouge_2 = [
          rouge_n([hyp], [ref], 2) for hyp, ref in zip(hypotheses, references)
      ]
      rouge_2_f, _, _ = map(np.mean, zip(*rouge_2))
      return rouge_2_f
docs: Calculate ROUGE-2 F1, precision, recall scores