code: def test_sum_metrics_to_data_dropped_public_partition(self):
      input = _get_default_sum_metrics(metric=pipeline_dp.Metrics.COUNT)
      output = cross_partition_combiners._sum_metrics_to_data_dropped(
          input,
          partition_keep_probability=1.0,
          dp_metric=pipeline_dp.Metrics.COUNT,
      )
      self.assertEqual(
          output,
          metrics.DataDropInfo(
              l0=2.0, linf=5.0, partition_selection=0.0
          ),
      )
  
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 8 for calling the PerPartitionToCrossPartitionMetrics obj's underlying member method code with example usage: obj.test_sum_metrics_to_data_dropped_public_partition() without return types