code: def setUp(self):
      self.args = Namespace()
      self.args.node_count = 1
      self.args.node_id = None
      if os.path.exists(command_path):
          shutil.rmtree(command_path)
  
file_path: nni/test/ut/tools/trial_tool/test_file_channel.py
imports: import json
  import os
  import random
  import shutil
  import string
  import sys
  import time
  import unittest
  from argparse import Namespace
  from datetime import datetime
  from nni.tools.trial_tool.base_channel import CommandType
  from nni.tools.trial_tool.file_channel import FileChannel, command_path, manager_commands_file_name
label_desc: Use image node_id 1 for calling the FileChannelTest obj's underlying member method code with example usage: obj.setUp() without return types