code: def test_merge_sparse(self):
      combiner = self._create_combiner()
      sparse_acc1 = ([1], [10], [100])
      acc1 = (sparse_acc1, None)
      sparse_acc2 = ([11], [2], [300])
      acc2 = (sparse_acc2, None)
      sparse, dense = combiner.merge_accumulators(acc1, acc2)
      self.assertSequenceEqual(sparse, ([1, 11], [10, 2], [100, 300]))
      self.assertIsNone(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 5 for calling the UtilityAnalysisCompoundCombinerTest obj's underlying member method code with example usage: obj.test_merge_sparse() without return types