code: def test_transformer_convert_llama_save_load(self):
      with tempfile.TemporaryDirectory(dir=output_dir) as tempdir:
          model = AutoModelForCausalLM.from_pretrained(
              llama_model_path, load_in_low_bit="asym_int4"
          )
          model.save_low_bit(tempdir)
          newModel = AutoModelForCausalLM.load_low_bit(tempdir)
          assert newModel is not None
  
file_path: BigDL/python/llm/test/convert/test_convert_model.py
imports: import pytest
  import os
  import tempfile
  from unittest import TestCase
  import shutil
  from bigdl.llm import llm_convert
  from bigdl.llm.transformers import AutoModelForCausalLM
  from bigdl.llm.optimize import optimize_model, load_low_bit, low_memory_init
label_desc: Use image node_id 8 for calling the TestConvertModel obj's underlying member method code with example usage: obj.test_transformer_convert_llama_save_load() without return types