code: def test_step(self, batch, batch_idx):
      output = self(batch)
      loss = self.loss(batch, output)
      return {"y": loss}
  
imports: from typing import Optional
  import torch
  from pytorch_lightning import LightningDataModule, LightningModule
  from torch.utils.data import DataLoader, Dataset, Subset
label_desc: Use image node_id 10 for calling the BoringModel obj's underlying member method code with example usage: obj.test_step(batch, batch_idx) and returns: dict