code: def test_external_sort_in_rdd(self):
      conf = SparkConf().set("spark.python.worker.memory", "1m")
      sc = SparkContext(conf=conf)
      lst = list(range(10240))
      random.shuffle(lst)
      rdd = sc.parallelize(lst, 4)
      self.assertEqual(sorted(lst), rdd.sortBy(lambda x: x).collect())
      sc.stop()
  
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 3 for calling the SorterTests obj's underlying member method code with example usage: obj.test_external_sort_in_rdd() without return types