code: def test_contribution_bounding_empty_col(self):
      input = []
      max_partitions_contributed = max_contributions_per_partition = 2
      bound_result = self._run_contribution_bounding(
          input,
          max_partitions_contributed,
          max_contributions_per_partition,
      )
  
      self.assertEmpty(bound_result)
  
file_path: pipelinedp/analysis/tests/contribution_bounders_test.py
imports: import collections
  from absl.testing import absltest
  from absl.testing import parameterized
  import pipeline_dp
  import analysis.contribution_bounders
label_desc: Use image node_id 2 for calling the SamplingL0LinfContributionBounderTest obj's underlying member method code with example usage: obj.test_contribution_bounding_empty_col() without return types