code: def test_aggregate_private_partition_selection_drop_many(self):
      # Arrange
      aggregator_params = pipeline_dp.AggregateParams(
          noise_kind=pipeline_dp.NoiseKind.GAUSSIAN,
          metrics=[agg.Metrics.COUNT],
          max_partitions_contributed=1,
          max_contributions_per_partition=1,
      )
  
      # Set a small budget for dropping most partition keys.
      budget_accountant = NaiveBudgetAccountant(
          total_epsilon=1, total_delta=1e-10
      )
  
      # Input collection has 100 elements, such that each privacy id
      # contributes 1 time and each partition has 1 element.
      col = list(range(100))
      data_extractor = pipeline_dp.DataExtractors(
          privacy_id_extractor=lambda x: x,
          partition_extractor=lambda x: f"pk{x}",
          value_extractor=lambda x: None,
      )
  
      engine = pipeline_dp.DPEngine(
          budget_accountant=budget_accountant,
          backend=pipeline_dp.LocalBackend(),
      )
  
      col = engine.aggregate(
          col=col,
          params=aggregator_params,
          data_extractors=data_extractor,
      )
      budget_accountant.compute_budgets()
  
      col = list(col)
  
      # Assert
  
      # Most partition should be dropped by private partition selection.
      # This test is non-deterministic, but it should pass with probability
      # very close to 1.
      self.assertLess(len(col), 5)
  
imports: import sys
  import unittest
  from typing import List, Optional, Tuple
  from unittest.mock import patch
  import numpy
  import apache_beam
  import apache_beam.testing.test_pipeline
  import apache_beam.testing.util
  import pydp.algorithms.partition_selection
  from absl.testing import absltest
  from absl.testing import parameterized
  import pipeline_dp
  from pipeline_dp import aggregate_params
  from pipeline_dp import budget_accounting
  from pipeline_dp import dp_computations
  from pipeline_dp.budget_accounting import NaiveBudgetAccountant
  from pipeline_dp.pipeline_backend import PipelineBackend
  from pipeline_dp.pipeline_functions import collect_to_container
  from pipeline_dp.report_generator import ReportGenerator
label_desc: Use image node_id 23 for calling the DpEngineTest obj's underlying member method code with example usage: obj.test_aggregate_private_partition_selection_drop_many() without return types