code: def forward(self, x):
      # in lightning,
      # forward defines the prediction/inference actions
      embedding = self.encoder(x)
      return embedding
  
file_path: pytorch-lightning/docs/source-app/code_samples/convert_pl_to_app/train.py
imports: import os
  import torch
  import torch.nn.functional
  from torch import nn
  from torch.utils.data import DataLoader, random_split
  from torchvision import transforms
  from torchvision.datasets import MNIST
  import lightning.pytorch
label_desc: Use image node_id 2 for calling the LitAutoEncoder obj's underlying member method code with example usage: obj.forward(x) and returns: embedding