code: def test_sample_combine_fn_no_input(self):
      slice_key = (("slice_feature", 1),)
      samples = [
          (
              slice_key,
              confidence_intervals_util.SampleMetrics(
                  sample_id=_FULL_SAMPLE_ID, metrics={}
              ),
          ),
          (
              slice_key,
              confidence_intervals_util.SampleMetrics(
                  sample_id=0, metrics={}
              ),
          ),
          (
              slice_key,
              confidence_intervals_util.SampleMetrics(
                  sample_id=1, metrics={}
              ),
          ),
      ]
  
      with beam.Pipeline() as pipeline:
          result = (
              pipeline
              | "Create" >> beam.Create(samples)
              | "CombineSamplesPerKey"
              >> beam.CombinePerKey(
                  _ValidateSampleCombineFn(
                      num_samples=2, full_sample_id=_FULL_SAMPLE_ID
                  )
              )
          )
  
          def check_result(got_pcoll):
              self.assertLen(got_pcoll, 1)
              accumulators_by_slice = dict(got_pcoll)
              self.assertIn(slice_key, accumulators_by_slice)
              accumulator = accumulators_by_slice[slice_key]
              self.assertEqual(2, accumulator.num_samples)
              self.assertIsInstance(accumulator.point_estimates, dict)
              self.assertIsInstance(accumulator.metric_samples, dict)
  
          util.assert_that(result, check_result)
  
file_path: model-analysis/tensorflow_model_analysis/evaluators/confidence_intervals_util_test.py
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import apache_beam
  from apache_beam.testing import util
  import numpy
  from numpy import testing
  from tensorflow_model_analysis.evaluators import confidence_intervals_util
  from tensorflow_model_analysis.metrics import binary_confusion_matrices
  from tensorflow_model_analysis.metrics import metric_types
label_desc: Use image node_id 3 for calling the ConfidenceIntervalsUtilTest obj's underlying member method code with example usage: obj.test_sample_combine_fn_no_input() without return types