code: def test_public_keys(self):
      query = (
          dataframes.QueryBuilder(get_pandas_df(), "privacy_key")
          .groupby(
              "group_key",
              max_groups_contributed=5,
              max_contributions_per_group=10,
              public_keys=["key1"],
          )
          .count()
          .build_query()
      )
  
      self.assertEqual(query._public_partitions, ["key1"])
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from collections import namedtuple
  import pandas
  from pyspark import sql
  from unittest import mock
  from unittest.mock import patch
  from pipeline_dp import dataframes
  import pipeline_dp
label_desc: Use image node_id 15 for calling the QueryBuilderTest obj's underlying member method code with example usage: obj.test_public_keys() without return types