code: def test_build_custom_arch(
      self, model_configs, custom_encoder, custom_decoder
  ):
      model = VAE_LinNF(
          model_configs, encoder=custom_encoder, decoder=custom_decoder
      )
  
      assert model.encoder == custom_encoder
      assert not model.model_config.uses_default_encoder
      assert model.decoder == custom_decoder
      assert not model.model_config.uses_default_decoder
  
      model = VAE_LinNF(model_configs, encoder=custom_encoder)
  
      assert model.encoder == custom_encoder
      assert not model.model_config.uses_default_encoder
      assert model.model_config.uses_default_decoder
  
      model = VAE_LinNF(model_configs, decoder=custom_decoder)
  
      assert model.model_config.uses_default_encoder
      assert model.decoder == custom_decoder
      assert not model.model_config.uses_default_decoder
  
imports: import os
  from copy import deepcopy
  import pytest
  import torch
  from pydantic import ValidationError
  from pythae.customexception import BadInheritanceError
  from pythae.models import AutoModel, VAE_LinNF, VAE_LinNF_Config
  from pythae.models.base.base_utils import ModelOutput
  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, NetBadInheritance
label_desc: Use image node_id 6 for calling the Test_Model_Building obj's underlying member method code with example usage: obj.test_build_custom_arch(model_configs, custom_encoder, custom_decoder) without return types