code: def test_step(self, batch, batch_idx, dataloader_idx=0):
      output_dict = self.evaluation_step(
          batch, batch_idx, dataloader_idx, "test"
      )
      if (
          isinstance(self.trainer.test_dataloaders, (list, tuple))
          and len(self.trainer.test_dataloaders) > 1
      ):
          self.test_step_outputs[dataloader_idx].append(output_dict)
      else:
          self.test_step_outputs.append(output_dict)
      return output_dict
  
imports: from abc import ABC, abstractmethod
  from typing import List, Union
  import hydra
  import torch
  from omegaconf import DictConfig, OmegaConf
  from pytorch_lightning import Trainer
  from nemo.collections.asr.metrics.audio import AudioMetricWrapper
  from nemo.core.classes import ModelPT
  from nemo.utils import logging, model_utils
label_desc: Use image node_id 9 for calling the AudioToAudioModel obj's underlying member method code with example usage: obj.test_step(batch, batch_idx, dataloader_idx) and returns: output_dict