question: find_unused_parameters in the lightning trainer (1.3.2)
context: 🐛 Bug
  If there are unsued parameters in the model, should we still explicitly mentioned the trainer as follows?
  plugins=[DDPPlugin(find_unused_parameters=True)]
   trainer = pl.Trainer.from_argparse_args( args, weights_summary=None,  callbacks=[logging_callback],  logger=logger,         plugins=[DDPPlugin(find_unused_parameters=True)], **train_params,)
answer: No, it is set to True by default and you want to turn it off unless you need it :)
  Reference:
  https://pytorch-lightning.readthedocs.io/en/1.3.3/benchmarking/performance.html#when-using-ddp-set-find-unused-parameters-false