code: def validation_step(self, *args, **kwargs):
      return self.training_step(*args, **kwargs)
  
file_path: pytorch-lightning/examples/fabric/build_your_own_trainer/run.py
imports: import lightning
  import torch
  from torchmetrics.functional.classification.accuracy import accuracy
  from trainer import MyCustomTrainer
label_desc: Use image node_id 5 for calling the MNISTModule obj's underlying member method code with example usage: obj.validation_step() and returns: self