code: def on_train_batch_start(self, trainer, pl_module, batch, *_):
      _device_check_helper(batch.device, pl_module.device)
  
imports: import pytest
  from lightning.pytorch import Callback, Trainer
  from lightning.pytorch.demos.boring_classes import BoringModel
  from tests_pytorch.helpers.runif import RunIf
label_desc: Use image node_id 1 for calling the BatchHookObserverCallback obj's underlying member method code with example usage: obj.on_train_batch_start(trainer, pl_module, batch) without return types