code: def run(self):
      if self.opt["port"] is None:
          port = None
      else:
          port = self.opt["port"]
      return launch_and_train(self.opt, port)
  
file_path: ParlAI/parlai/scripts/multiprocessing_train.py
imports: import torch
  import os
  import signal
  import traceback
  import parlai.scripts.train_model
  import parlai.utils.distributed
  import parlai.utils.fsdp
  from parlai.core.script import ParlaiScript, register_script
label_desc: Use image node_id 2 for calling the MultiProcessTrain obj's underlying member method code with example usage: obj.run() and returns: launch_and_train