code: def setUpClass(cls):
      conf = pyspark.SparkConf()
      cls.sc = SparkContext.getOrCreate(conf=conf)
  
imports: import pyspark
  from pyspark import SparkContext
  from absl.testing import parameterized
  from unittest.mock import patch
  import unittest
  import sys
  import collections
  import pipeline_dp
  from pipeline_dp import aggregate_params
  from pipeline_dp import budget_accounting, private_spark
label_desc: Use image node_id 1 for calling the PrivateRDDTest obj's underlying member method code with example usage: obj.setUpClass(cls) without return types