code: def test_different_rouge(self):
      ref = "this is a string"
      self.assertDictClose(
          metrics.rouge([ref, ref], ["", ""]),
          {"rouge1": 0, "rouge2": 0, "rougeLsum": 0},
      )
      self.assertDictClose(
          metrics.rouge_mean([ref, ref], ["", ""]),
          {"rouge1": 0, "rouge2": 0, "rougeLsum": 0},
      )
  
imports: from unittest import mock
  from absl.testing import absltest
  import numpy
  import seqio
  import sklearn.metrics
  from t5.evaluation import metrics
  from t5.evaluation import test_utils
label_desc: Use image node_id 5 for calling the MetricsTest obj's underlying member method code with example usage: obj.test_different_rouge() without return types