code: def main(cfg) -> None:
      logging.info(
          "\n\n************** Experiment configuration ***********"
      )
      logging.info(f"\n{OmegaConf.to_yaml(cfg)}")
  
      trainer = MegatronTrainerBuilder(cfg).create_trainer()
      exp_manager(trainer, cfg.exp_manager)
  
      model = MegatronGPTModel(cfg.model, trainer)
  
      trainer.fit(model)
  
imports: import torch.multiprocessing
  from omegaconf.omegaconf import OmegaConf, open_dict
  from nemo.collections.nlp.models.language_modeling.megatron_gpt_model import MegatronGPTModel
  from nemo.collections.nlp.parts.megatron_trainer_builder import MegatronTrainerBuilder
  from nemo.core.config import hydra_runner
  from nemo.utils import logging
  from nemo.utils.exp_manager import exp_manager
label_desc: Use image node_id 1 for calling a global function with example usage: main(cfg) without return types