code: def _step(self, batch, validation):
      inputs = batch
      outputs = self(**inputs)
      loss = outputs.loss
      return loss
  
file_path: SynapseML/deep-learning/src/main/python/synapse/ml/dl/LitDeepTextModel.py
imports: import inspect
  import pytorch_lightning
  import torch
  import torch.nn.functional
  import torch.optim
  from pytorch_lightning.utilities import _module_available
label_desc: Use image node_id 8 for calling the LitDeepTextModel obj's underlying member method code with example usage: obj._step(batch, validation) and returns: loss