code: def training_step(self, batch, batch_idx) -> None:
      self.log("train_epoch", self.trainer.current_epoch)
      self.log_dict({"train_epoch_dict": self.trainer.current_epoch})
  
file_path: lightly/tests/utils/benchmarking/test_metric_callback.py
imports: import torch
  from pytorch_lightning import LightningModule, Trainer
  from torch.utils.data import DataLoader
  from torchvision.datasets import FakeData
  from torchvision.transforms import ToTensor
  from lightly.utils.benchmarking import MetricCallback
label_desc: Use image node_id 2 for calling the _DummyModule obj's underlying member method code with example usage: obj.training_step(batch, batch_idx) without return types