docstr: TearDown function needs to be called at the end of each test to free the GPU memory and cache, also to
  avoid unexpected behaviors. Please see: https://discuss.pytorch.org/t/how-can-we-release-gpu-memory-cache/14530/27
code: def tearDown(self):
      """
      TearDown function needs to be called at the end of each test to free the GPU memory and cache, also to
      avoid unexpected behaviors. Please see: https://discuss.pytorch.org/t/how-can-we-release-gpu-memory-cache/14530/27
      """
      super().tearDown()
      del self.model_fp16
      del self.model_4bit
  
      gc.collect()
      torch.cuda.empty_cache()
  
imports: import gc
  import tempfile
  import unittest
  import torch
  import torch.nn
  from accelerate import Accelerator, init_empty_weights
  from accelerate.test_utils import require_bnb, require_cuda, require_huggingface_suite, require_multi_gpu, slow
  from accelerate.utils.bnb import load_and_quantize_model
  from accelerate.utils.dataclasses import BnbQuantizationConfig
label_desc: Use image node_id 2 for calling the Bnb4BitTestLoadedModel obj's underlying member method code with example usage: obj.tearDown() without return types