code: def test_merge_metric_utility(self):
      utility1 = _get_metric_utility(coef=2)
      utility2 = _get_metric_utility(coef=3)
      expected = _get_metric_utility(coef=5)
      cross_partition_combiners._merge_metric_utility(
          utility1, utility2
      )
      self.assertEqual(utility1, expected)
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import dataclasses
  import math
  from unittest import mock
  from unittest.mock import patch
  from analysis import metrics
  from analysis import cross_partition_combiners
  import pipeline_dp
label_desc: Use image node_id 2 for calling the MergeMetricsTests obj's underlying member method code with example usage: obj.test_merge_metric_utility() without return types