code: def demo_data(self):
      data = torch.load(
          os.path.join(PATH, "data/mnist_clean_train_dataset_sample")
      )[:]
      return data
  
imports: import os
  from copy import deepcopy
  import pytest
  import torch
  from pythae.customexception import BadInheritanceError
  from pythae.models import RHVAE, AutoModel, RHVAEConfig
  from pythae.models.rhvae.rhvae_config import RHVAEConfig
  from pythae.pipelines import GenerationPipeline, TrainingPipeline
  from pythae.samplers import GaussianMixtureSamplerConfig, IAFSamplerConfig, MAFSamplerConfig, NormalSamplerConfig, TwoStageVAESamplerConfig
  from pythae.trainers import BaseTrainer, BaseTrainerConfig
  from tests.data.custom_architectures import Decoder_AE_Conv, Encoder_VAE_Conv, Metric_MLP_Custom, NetBadInheritance
label_desc: Use image node_id 1 for calling the Test_NLL_Compute obj's underlying member method code with example usage: obj.demo_data() and returns: data