class_docstr: Base class for unittests using Spark.  Sets up and tears down a cluster per test class
code: def tearDownClass(cls):
      cls.spark.stop()
      cls.sc.stop()
  
file_path: TensorFlowOnSpark/tests/test.py
imports: import os
  import unittest
  from pyspark import SparkConf, SparkContext
  from pyspark.sql import SparkSession
label_desc: Use image node_id 2 for calling the SparkTest obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types