code: def test_stopiteration_is_raised(self):
      def stopit(*args, **kwargs):
          raise StopIteration()
  
      def legit_create_combiner(x):
          return [x]
  
      def legit_merge_value(x, y):
          return x.append(y) or x
  
      def legit_merge_combiners(x, y):
          return x.extend(y) or x
  
      data = [(x % 2, x) for x in range(100)]
  
      # wrong create combiner
      m = ExternalMerger(
          Aggregator(stopit, legit_merge_value, legit_merge_combiners),
          20,
      )
      with self.assertRaises((Py4JJavaError, RuntimeError)):
          m.mergeValues(data)
  
      # wrong merge value
      m = ExternalMerger(
          Aggregator(
              legit_create_combiner, stopit, legit_merge_combiners
          ),
          20,
      )
      with self.assertRaises((Py4JJavaError, RuntimeError)):
          m.mergeValues(data)
  
      # wrong merge combiners
      m = ExternalMerger(
          Aggregator(legit_create_combiner, legit_merge_value, stopit),
          20,
      )
      with self.assertRaises((Py4JJavaError, RuntimeError)):
          m.mergeCombiners(map(lambda x_y1: (x_y1[0], [x_y1[1]]), data))
  
imports: import random
  import unittest
  import tempfile
  import os
  from py4j.protocol import Py4JJavaError
  from pyspark import shuffle, CPickleSerializer, SparkConf, SparkContext
  from pyspark.shuffle import Aggregator, ExternalMerger, ExternalSorter, SimpleAggregator, Merger, ExternalGroupBy
label_desc: Use image node_id 9 for calling the MergerTests obj's underlying member method code with example usage: obj.test_stopiteration_is_raised() and returns: list, unknown, unknown