code: def test_merge_sparse_result_dense(self):
      combiner = self._create_combiner()
      sparse_acc1 = ([1, 3], [10, 20], [100, 200])
      acc1 = (sparse_acc1, None)
      sparse_acc2 = ([11], [2], [300])
      acc2 = (sparse_acc2, None)
      sparse, dense = combiner.merge_accumulators(acc1, acc2)
      self.assertIsNone(sparse)
      self.assertEqual(
          (3, ((15, 0, -10, -4.973333333333334, 0.04308888888888889),)),
          dense,
      )
  
imports: import dataclasses
  import numpy
  from absl.testing import absltest
  from absl.testing import parameterized
  from unittest.mock import patch
  from typing import Tuple
  import pipeline_dp
  from analysis import per_partition_combiners
  from analysis import metrics
  from analysis.tests import common
label_desc: Use image node_id 6 for calling the UtilityAnalysisCompoundCombinerTest obj's underlying member method code with example usage: obj.test_merge_sparse_result_dense() without return types