code: def test_train(self, model_type: str):
      model_id = MODELS_DICT[model_type]
      self._test_train_decoder(model_id, model_type=model_type)
  
imports: import gc
  import unittest
  import pytest
  import torch
  from parameterized import parameterized
  from testing_utils import MODELS_DICT, BetterTransformersTestMixin
  from transformers import AutoModelForCausalLM, AutoTokenizer
  from optimum.bettertransformer import BetterTransformer
  from optimum.utils import BloomDummyPastKeyValuesGenerator, DummyPastKeyValuesGenerator, NormalizedConfigManager
  from optimum.utils.testing_utils import grid_parameters, require_accelerate, require_torch_gpu
label_desc: Use image node_id 7 for calling the BetterTransformersDecoderTest obj's underlying member method code with example usage: obj.test_train(model_type) without return types