class_docstr: Tests for TopkUniquesStatsGenerator.
class_docstr_tok: ["Tests","for","TopkUniquesStatsGenerator","."]
code: def test_topk_uniques_with_empty_record_batch(self):
      examples = [pa.RecordBatch.from_arrays([], [])]
      expected_result = []
      generator = (
          top_k_uniques_stats_generator.TopKUniquesStatsGenerator(
              num_top_values=4, num_rank_histogram_buckets=3
          )
      )
      self.assertSlicingAwareTransformOutputEqual(
          examples,
          generator,
          expected_result,
          add_default_slice_key_to_input=True,
          add_default_slice_key_to_output=True,
      )
  
imports: from absl.testing import absltest
  import pyarrow
  from tensorflow_data_validation import types
  from tensorflow_data_validation.statistics.generators import top_k_uniques_stats_generator
  from tensorflow_data_validation.utils import test_util
  from tensorflow_data_validation.utils.example_weight_map import ExampleWeightMap
  from google.protobuf import text_format
  from tensorflow_metadata.proto.v0 import schema_pb2
  from tensorflow_metadata.proto.v0 import statistics_pb2
label_desc: Use image node_id 6 for calling the TopkUniquesStatsGeneratorTest obj's underlying member method code with example usage: obj.test_topk_uniques_with_empty_record_batch() without return types