code: def test_model_train_output(self, ae, demo_data):
      ae.train()
  
      out = ae(demo_data)
  
      assert isinstance(out, ModelOutput)
  
      assert set(["loss", "recon_x", "z"]) == set(out.keys())
  
      assert out.z.shape[0] == demo_data["data"].shape[0]
      assert out.recon_x.shape == demo_data["data"].shape
  
imports: import os
  from copy import deepcopy
  import pytest
  import torch
  from pythae.customexception import BadInheritanceError
  from pythae.models import AE, AEConfig, AutoModel
  from pythae.models.base.base_utils import ModelOutput
  from pythae.pipelines import GenerationPipeline, TrainingPipeline
  from pythae.samplers import GaussianMixtureSamplerConfig, IAFSamplerConfig, MAFSamplerConfig, NormalSamplerConfig
  from pythae.trainers import BaseTrainer, BaseTrainerConfig
  from tests.data.custom_architectures import Decoder_AE_Conv, Encoder_AE_Conv, NetBadInheritance
label_desc: Use image node_id 3 for calling the Test_Model_forward obj's underlying member method code with example usage: obj.test_model_train_output(ae, demo_data) without return types