code: def test_43B_tokenizer_mask_assistant_nolabel(self):
      tokenizer = get_nmt_tokenizer(
          library="sentencepiece", tokenizer_model=TOKENIZER_FILE_43B
      )
      self._mask_assistant_nolabel_test(
          tokenizer, tokenizer.ids_to_text
      )
  
imports: import json
  import os
  import random
  from functools import partial
  import pytest
  from nemo.collections.nlp.data.language_modeling.megatron.gpt_sft_chat_dataset import GPTSFTChatDataset, get_prompt_template_example
  from nemo.collections.nlp.modules.common.tokenizer_utils import get_nmt_tokenizer
label_desc: Use image node_id 15 for calling the TestGPTSFTChatDataset obj's underlying member method code with example usage: obj.test_43B_tokenizer_mask_assistant_nolabel() without return types