class_docstr: Builder type to hide complex configuration of PTL Trainers for Megatron LLM models.
  Can be extended to change behavior for a specific model.
code: def create_trainer(self, callbacks=None) -> Trainer:
      strategy = self._training_strategy()
      plugins = self._plugins()
      if callbacks is None:
          callbacks = [CustomProgressBar()]
      return Trainer(
          plugins=plugins,
          strategy=strategy,
          **self.cfg.trainer,
          callbacks=callbacks,
      )
  
imports: import sys
  from typing import Union
  from omegaconf import DictConfig
  from pytorch_lightning import Trainer
  from pytorch_lightning.callbacks import ModelSummary
  from pytorch_lightning.plugins.environments import TorchElasticEnvironment
  from nemo.collections.nlp.parts.nlp_overrides import CustomProgressBar, GradScaler, MegatronHalfPrecisionPlugin, NLPDDPStrategy, NLPDDPStrategyNotebook, NLPFSDPStrategy, PipelineMixedPrecisionPlugin
  from nemo.utils import logging
label_desc: Use image node_id 5 for calling the MegatronTrainerBuilder obj's underlying member method code with example usage: obj.create_trainer(callbacks) and returns: Trainer