code: def tearDown(self) -> None:
      self.fl_server.stop()
  
imports: import multiprocessing
  import threading
  from multiprocessing import Process
  import unittest
  import numpy
  import pandas
  import os
  import torch
  from bigdl.ppml.fl.nn.fl_context import init_fl_context
  from bigdl.ppml.fl.nn.pytorch.utils import set_one_like_parameter
  from bigdl.ppml.fl.nn.fl_server import FLServer
  from torch import Tensor, nn
  import logging
  from bigdl.ppml.fl.estimator import Estimator
  from bigdl.ppml.fl.utils import FLTest
  from typing import List
label_desc: Use image node_id 3 for calling the TestLogisticRegression obj's underlying member method code with example usage: obj.tearDown() without return types