code: def tearDown(self):
      teardown_imports()
      del self.pretrain_model
      gc.collect()
  
imports: import gc
  import unittest
  import tests.test_utils
  import torch
  from mmf.common.sample import SampleList
  from mmf.models.vilt import ViLTImageEmbedding, ViLTTextEmbedding
  from mmf.utils.build import build_model
  from mmf.utils.configuration import Configuration
  from mmf.utils.env import setup_imports, teardown_imports
  from mmf.utils.general import get_current_device
  from tests.test_utils import skip_if_old_transformers
  from torch import nn
label_desc: Use image node_id 2 for calling the TestViltPretrained obj's underlying member method code with example usage: obj.tearDown() without return types