code: def trainer_cls(self, configs_and_models):
      if configs_and_models[1].name == "BaseTrainerConfig":
          return BaseTrainer
      elif (
          configs_and_models[1].name == "CoupledOptimizerTrainerConfig"
      ):
          return CoupledOptimizerTrainer
      elif configs_and_models[1].name == "AdversarialTrainerConfig":
          return AdversarialTrainer
      else:
          return CoupledOptimizerAdversarialTrainer
  
imports: import os
  from collections import Counter
  import pytest
  import torch
  from pythae.models import AE, RAE_L2, VAEGAN, Adversarial_AE, Adversarial_AE_Config, AEConfig, RAE_L2_Config, VAEGANConfig
  from pythae.trainers import *
  from pythae.trainers.training_callbacks import *
label_desc: Use image node_id 4 for calling the Test_TrainersCalls obj's underlying member method code with example usage: obj.trainer_cls(configs_and_models) and returns: BaseTrainer, CoupledOptimizerTrainer, AdversarialTrainer, CoupledOptimizerAdversarialTrainer