class_docstr: Class for launcher.
class_docstr_tok: ["Class","for","launcher","."]
code: def set_env(self, env_name, env_value):
      if not env_value:
          logger.warning("%s is None", env_name)
      if env_name not in os.environ:
          os.environ[env_name] = env_value
      elif os.environ[env_name] != env_value:
          logger.warning(
              "Overriding value with the one set in environment variable: %s. \
  Value applied: %s. Value ignored: %s",
              env_name,
              os.environ[env_name],
              env_value,
          )
      self.log_env_var(env_name)
  
imports: import glob
  import logging
  import os
  import platform
  import re
  import subprocess
  import sys
  from argparse import ArgumentParser, RawTextHelpFormatter, REMAINDER
  from os.path import expanduser
  from typing import Dict, List
  from torch.distributed.elastic.multiprocessing import start_processes, Std
label_desc: Use image node_id 6 for calling the _Launcher obj's underlying member method code with example usage: obj.set_env(env_name, env_value) without return types