code: def test_create_accumulator(self):
      combiner = self._create_combiner()
      report1 = _get_utility_report(coef=2)
      acc1 = ((1,), report1, 0.5)
      report2 = _get_utility_report(coef=5)
      acc2 = ((3,), report2, 0.5)
      expected_report = _get_utility_report(coef=7)
      (
          sum_actual,
          output_report,
          total_weight,
      ) = combiner.merge_accumulators(acc1, acc2)
      self.assertEqual(sum_actual, (4,))
      self.assertEqual(output_report, expected_report)
      self.assertEqual(total_weight, 1)
  
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 5 for calling the CrossPartitionCombiner obj's underlying member method code with example usage: obj.test_create_accumulator() without return types