code: def get_command(test_case_config, commandKey):
      command = test_case_config.get(commandKey)
      if commandKey == "launchCommand":
          assert command is not None
      if command is None:
          return None
  
      # replace variables
      for k in it_variables:
          command = command.replace(k, it_variables[k])
  
      # hack for windows, not limited to local training service
      if sys.platform == "win32":
          command = command.replace("python3", "python")
  
      return command
  
imports: import argparse
  import datetime
  import json
  import os
  import subprocess
  import sys
  import time
  import yaml
  import validators
  from utils import CLEAR, EXPERIMENT_URL, GREEN, RED, REST_ENDPOINT, STATUS_URL, TRIAL_JOBS_URL, deep_update, dump_yml_content, get_experiment_dir, get_experiment_id, get_experiment_status, get_failed_trial_jobs, get_trial_stats, get_yml_content, parse_max_duration_time, print_experiment_log, print_trial_job_log, wait_for_port_available
label_desc: Use image node_id 6 for calling a global function with example usage: get_command(test_case_config, commandKey) and returns: command, None