code: def test_accumulator_combiner(self):
      with beam.Pipeline() as pipeline:
          result = (
              pipeline
              | "Create" >> beam.Create([[1], [2]])
              | "AccumulatorCombine"
              >> beam.CombineGlobally(
                  jackknife._AccumulatorCombineFn(
                      ListCombineFnAddInputNotImplemented(
                          extract_output_append=3
                      )
                  )
              )
          )
  
          def check_result(got_pcoll):
              self.assertLen(got_pcoll, 1)
              self.assertEqual(got_pcoll[0], [1, 2, 3])
  
          util.assert_that(result, check_result)
  
imports: import functools
  from absl.testing import absltest
  import apache_beam
  from apache_beam.testing import util
  from tensorflow_model_analysis.api import types
  from tensorflow_model_analysis.evaluators import confidence_intervals_util
  from tensorflow_model_analysis.evaluators import jackknife
  from tensorflow_model_analysis.metrics import binary_confusion_matrices
  from tensorflow_model_analysis.metrics import metric_types
label_desc: Use image node_id 2 for calling the JackknifeTest obj's underlying member method code with example usage: obj.test_accumulator_combiner() without return types