code: def tearDown(self):
      client = reservation.Client(self.server_addr)
      client.request_stop()
      client.close()
  
file_path: TensorFlowOnSpark/tests/test_TFSparkNode.py
imports: import argparse
  import os
  import random
  import unittest
  from tensorflowonspark import gpu_info, reservation, TFSparkNode
  from unittest.mock import patch
label_desc: Use image node_id 2 for calling the TFSparkNodeTest obj's underlying member method code with example usage: obj.tearDown() without return types